Quotes about deduction (121 quotes) | Quotes of famous people

“But instinct is something which transcends knowledge. We have, undoubtedly, certain finer fibers that enable us to perceive truths when logical deduction, or any other willful effort of the brain, is futile.”

Nikola Tesla (1856–1943) Serbian American inventor

Source: My Inventions (1919)
Context: He declared that it could not be done and did me the honor of delivering a lecture on the subject, at the conclusion he remarked, "Mr. Tesla may accomplish great things, but he certainly will never do this. It would be equivalent to converting a steadily pulling force, like that of gravity into a rotary effort. It is a perpetual motion scheme, an impossible idea." But instinct is something which transcends knowledge. We have, undoubtedly, certain finer fibers that enable us to perceive truths when logical deduction, or any other willful effort of the brain, is futile.

Truth , Knowledge , Effort

“Sometimes the truth is arrived at by adding all the little lies together and deducting them from the totality of what is known.”

Terry Pratchett book Going Postal

Source: Going Postal

Truth

“The psycho-physiological hypothesis is both inductively and deductively the sine qua non of the science of psychology.”

Boris Sidis (1867–1923) American psychiatrist

Source: The Foundations of Normal and Abnormal Psychology (1914), p. 86

Science

“In a certain sense all knowledge is inductive. We can only learn the laws and relations of things in nature by observing those things. But the knowledge gained from the senses is knowledge only of particular facts, and we require some process of reasoning by which we may collect out of the facts the laws obeyed by them. Experience gives us the materials of knowledge: induction digests those materials, and yields us general knowledge. When we possess such knowledge, in the form of general propositions and natural laws, we can usefully apply the reverse process of deduction to ascertain the exact information required at any moment. In its ultimate foundation, then, all knowledge is inductive—in the sense that it is derived by a certain inductive reasoning from the facts of experience.”

William Stanley Jevons (1835–1882) English economist and logician

Source: The Principles of Science: A Treatise on Logic and Scientific Method (1874) Vol. 1, p. 14

Law , Nature , Knowledge , Sense

“I may as well say at once that I do not distinguish between inference and deduction. What is called induction appears to me to be either disguised deduction or a mere method of making plausible guesses.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

Principles of Mathematics (1903), Ch. II: Symbolic Logic, p. 11
1900s

Appearance

“Essentially, economic analysis consists of: (1) an understanding of the categories of action and an understanding of the meaning of a change in values, costs, technological knowledge, etc.; (2) a description of a situation in which these categories assume concrete meaning, where definite people are identified as actors with definite objects specified as their means of action, with definite goals identified as values and definite things specified as costs; and (3) a deduction of the consequences that result from the performance of some specified action in this situation, or of the consequences that result for an actor if this situation is changed in a specified way. And this deduction must yield a priori-valid conclusions, provided there is no flaw in the very process of deduction and the situation and the change introduced into it being given, and a priori—valid conclusions about reality if the situation and situation—change, as described, can themselves be identified as real, because then their validity would ultimately go back to the indisputable validity of the categories of action.”

Hans-Hermann Hoppe book A Theory of Socialism and Capitalism

A Theory of Socialism and Capitalism: Economics, Politics, and Ethics (Kluwer: 1989): 118-19.
A Theory of Socialism and Capitalism (1989)

People , Way , Understanding , Knowledge

“So much of modern mathematical work is obviously on the border-line of logic, so much of modern logic is symbolic and formal, that the very close relationship of logic and mathematics has become obvious to every instructed student. The proof of their identity is, of course, a matter of detail: starting with premisses which would be universally admitted to belong to logic, and arriving by deduction at results which as obviously belong to mathematics, we find that there is no point at which a sharp line can be drawn, with logic to the left and mathematics to the right. If there are still those who do not admit the identity of logic and mathematics, we may challenge them to indicate at what point, in the successive definitions and deductions of Principia Mathematica, they consider that logic ends and mathematics begins. It will then be obvious that any answer must be quite arbitrary.”

Bertrand Russell (1872–1970) logician, one of the first analytic philosophers and political activist

Source: 1910s, Introduction to Mathematical Philosophy (1919), Ch. 18: Mathematics and Logic

Mathematics , Universe , Success

“It remains to discuss briefly what general requirements may be justly laid down for the solution of a mathematical problem. I should say first of all, this: that it shall be possible to establish the correctness of the solution by means of a finite number of steps based upon a finite number of hypotheses which are implied in the statement of the problem and which must always be exactly formulated. This requirement of logical deduction by means of a finite number of processes is simply the requirement of rigor in reasoning.”

David Hilbert Mathematical Problems

Mathematical Problems (1900)

Mathematics , Problem

“It seems that scientists are often attracted to beautiful theories in the way that insects are attracted to flowers — not by logical deduction, but by something like a sense of smell.”

Steven Weinberg (1933) American theoretical physicist

Physics Today (November 2005) page 35

Beauty , Way , Flowers , Sense

“Wherever Mathematics is mixed up with anything, which is outside its field, you will find attempts to demonstrate these merely conventional propositions a priori, and it will be your task to find out the false deduction in each case.”

Carl Gustav Jacob Jacobi (1804–1851) German mathematician

Vorlesungen über analytische Mechanik [Lectures on Analytical Mechanics] (1847/48; edited by Helmut Pulte in 1996).

Mathematics , Falseness

“The Conceptual apparatus of the theory and the emotions connected with its application, having penetrated all means of communication, all actions, and indeed the whole life of the community, now guarantees the success of methods such as transcendental deduction, analysis of usage, phenomenological analysis - which are means for further solidifying the myth… At the same time it is evident that all contact with the world is lost and the stability achieved, the semblance of absolute truth is nothing but absolute conformism.”

Paul Karl Feyerabend book Against Method

Pg 44&45
Against Method (1975)
Context: [continued conjecture on empiricism] At this point an "empirical" theory of the kind described becomes almost indistinguishable from a second-rate myth. In order to realize this, we need only consider a myth such as the myth of witchcraft and of demonic possession that was developed by the Roman Catholic theologians and that dominated 15th-, 16th- and 17th-century thought on the European continent. This myth is a complex explanatory system that contains numerous auxiliary hypotheses designed to cover special cases, so it easily achieves a high degree of confirmation on the basis of observation. It has been taught for a long time; its content is enforced by fear, prejudice, and ignorance, as well as by a jealous and cruel priesthood. Its ideas penetrate the most common idiom, infect all modes of thinking and many decisions which mean a great deal in human life. It provides models for the explanation of a conceivable event - Conceivable, that is, for those who have accepted it. This being the case, its key terms will be fixed in an unambiguous manner and the idea (which may have led to such a procedure in the first place) that they are copies of unchanging entities and that change of meaning, if it should happen, is due to human mistake - This idea will now be very plausible. Such plausibility reinforces all the manoeuvres which are used for the preservation of the myth (elimination of opponents included). The Conceptual apparatus of the theory and the emotions connected with its application, having penetrated all means of communication, all actions, and indeed the whole life of the community, now guarantees the success of methods such as transcendental deduction, analysis of usage, phenomenological analysis - which are means for further solidifying the myth... At the same time it is evident that all contact with the world is lost and the stability achieved, the semblance of absolute truth is nothing but absolute conformism. For how can we possibly test, or improve upon the truth of a theory if it is built in such a manner then any conceivable event can be described, and explained, in terms of its principles? The only way of investigating such all-embracing principles would be to compare them with a different set of equally all embracing principles- but this procedure has been excluded from the very beginning.

Life , Truth , World , Communication

“Much less are children capable of reasonings from remote principles. They cannot conceive the force of long deductions. The reasons that move them must be obvious, and level to their thoughts, and such as may be felt and touched. But yet, if their age, temper, and inclination be consider'd, they will never want such motives as may be sufficient to convince them.”

John Locke book Some Thoughts Concerning Education

Sec. 81
Some Thoughts Concerning Education (1693)
Context: The foundations on which several duties are built, and the foundations of right and wrong from which they spring, are not perhaps easily to be let into the minds of grown men, not us'd to abstract their thoughts from common received opinions. Much less are children capable of reasonings from remote principles. They cannot conceive the force of long deductions. The reasons that move them must be obvious, and level to their thoughts, and such as may be felt and touched. But yet, if their age, temper, and inclination be consider'd, they will never want such motives as may be sufficient to convince them.

Children , Age , Motivation

“May the IRS find that you deduct your pet sheep as an entertainment expense.”

Christopher Moore book Practical Demonkeeping

Author's Blessing
Lamb: The Gospel According to Biff, Christ's Childhood Pal (2002)
Source: Practical Demonkeeping
Context: If you have come to these pages for laughter, may you find it.
If you are here to be offended, may your ire rise and your blood boil.
If you seek an adventure, may this song sing you away to blissful escape.
If you need to test or confirm your beliefs, may you reach comfortable conclusions.
All books reveal perfection, by what they are or what they are not.
May you find that which you seek, in these pages or outside them.
May you find perfection, and know it by name.

“Whatever lies beyond the limits of experience, and claims another origin than that of induction and deduction from established data, is illegitimate.”

George Henry Lewes (1817–1878) British philosopher

Vol. 1, p. 17
The Foundations of a Creed (1874-5)

“By induction we gain no certain knowledge; but by observation, and the inverse use of deductive reasoning, we estimate the probability that an event which has occurred was preceded by conditions of specified character, or that such conditions will be followed by the event. …I have no objection to use the words cause and causation, provided they are never allowed to lead us to imagine that our knowledge of nature can attain to certainty. …We can never recur too often to the truth that our knowledge of the laws and future events of the external world are only probable.”

William Stanley Jevons (1835–1882) English economist and logician

Source: The Principles of Science: A Treatise on Logic and Scientific Method (1874) Vol. 1, pp. 257, 260 & 271

Truth , World , Law , Imagination

“Fancy what a game at chess would be if all the chessmen had passions and intellects, more or less small and cunning; if you were not only uncertain about your adversary's men, but a little uncertain also about your own; if your knight could shuffle himself on to a new square by the sly; if your bishop, in disgust at your castling, could wheedle your pawns out of their places; and if your pawns, hating you because they are pawns, could make away from their appointed posts that you might get checkmate on a sudden. You might be the longest-headed of deducted reasoners, and yet you might be beaten by your own pawns. You would be especially likely to be beaten, if you depended arrogantly on your mathematical imagination, and regarded your passionate pieces with contempt.
Yet this imaginary chess is easy compared with the game a man has to play against his fellow-men with other fellow-men for his instruments. He thinks himself sagacious, perhaps, because he trusts no bond except that of self-interest; but the only self-interest he can safely rely on is what seems to be such to the mind he would use or govern. Can he ever be sure of knowing this?”

George Eliot book Felix Holt, the Radical

Start of Chapter 29 (at page 237)
Felix Holt, the Radical (1866)

Men , Hate , Imagination , Game

“Instead of being given a true, simple—and therefore easily understandable—picture of Islamic Law, the Muslims are presented with a gigantic, many-sided edifice of fiqhi deductions and interpretations (a secondhand Islam, as it were) arrived at by individual scholars and schools of thought a thousand years ago.”

Muhammad Asad book The Principles of State and Government in Islam

Source: The Principles of State and Government in Islam (1961), Chapter 6: Conclusion, p 100

School , Law , Understanding

“You've heard about the controversies within the bill, the process about the bill, one or the other. But I don't know if you have heard that it is legislation for the future, not just about health care for America, but about a healthier America, where preventive care is not something that you have to pay a deductible for or out of pocket. Prevention, prevention, prevention—it's about diet, not diabetes. It's going to be very, very exciting. But we have to pass the bill so that you can find out what is in it, away from the fog of the controversy.”

Nancy Pelosi (1940) American politician, first female Speaker of the House of Representatives, born 1940

9 March, 2010. Source: http://www.slate.com/id/2279128/ Having to pass a bill to know what is does is a Grin and Bear It cartoon punchline http://talkingpointsmemo.com/edblog/john-roberts-obamacare-cartoon from 1947, paraphased in a 1948 Indiana Law Journal article by then Supreme Court Justice Felix Frankfurter. http://www.repository.law.indiana.edu/cgi/viewcontent.cgi?article=3871&context=ilj Frankfurter was in turn cited in 2015's decision in King v. Burwell, authored by Chief Justice John Roberts, which turned on a complication in the very law resulting from the bill Pelosi was above describing. http://www.supremecourt.gov/opinions/14pdf/14-114_qol1.pdf
2010s

Health , Future

“From all the properties of man and of nature, from all the various branches of science, from all the deductions of human reason, the general corollary, admitted by Hindus, Arabs, and Tartars, by Persians, and by Chinese, is the supremacy of an all-creating and all-preserving spirit, infinitely wise, good, and powerful, but infinitely removed from the comprehension of his most exalted creatures; nor are there in any language (the ancient Hebrew always excepted) more pious and sublime addresses to the being of beings, more splendid enumerations of his attributes, or more beautiful descriptions of his visible works, than in Arabick, Persian, and Sanscrit, especially in the Koran, the introductions to the poems of Sadi', Niza'm'i and Firdaus'i, the four Védas, and many parts of the numerous Puránas: but supplication and praise would not satisfy the boundless imagination of the Vedánti and Sufi theologists, who blending uncertain metaphysicks with undoubted principles of religion, have presumed to reason confidently on the very nature and essence of the divine spirit, and asserted in a very remote age, what multitudes of Hindus and Muselmans assert… that all spirit is homogeneous, that the spirit of God is in kind the same with that of man, though differing from it infinitely in degree, and that, as material substance is mere illusion, there exists in this universe only one generick spiritual substance, the sole primary cause, efficient, substantial and formal of all secondary causes and of all appearances whatever, but endued in its highest degree, with a sublime providential wisdom, and proceeding by ways incomprehensible to the spirits which emane from it; an opinion which Gotama never taught, and which we have no authority to believe, but which, as it is grounded on the doctrine of an immaterial creator supremely wise, and a constant preserver supremely benevolent, differs as widely from the pantheism of Spinoza and Toland, as the affirmation of a proposition differs from the negation of it; though the last named professor of that insane philosophy had the baseness to conceal his meaning under the very words of Saint Paul, which are cited by Newton for a purpose totally different, and has even used a phrase, which occurs, indeed, in the Véda, but in a sense diametrically opposite to that, which he would have given it. The passage to which I allude is in a speech of Varuna to his son, where he says, "That spirit, from which these created beings proceed; through which having proceeded from it, they live; toward which they tend and in which they are ultimately absorbed, that spirit study to know; that spirit is the Great One."”

William Jones (1746–1794) Anglo-Welsh philologist and scholar of ancient India

"On the Philosophy of the Asiatics" (1794)

Wisdom , God , Age , Religion

“Experience has convinced me that the proper way of teaching is to bring together that which is simple from all quarters, and, if I may use such a phrase, to draw upon the surface of the subject a proper mean between the line of closest connexion and the line of easiest deduction. This was the method followed by Euclid, who, fortunately for us, never dreamed of a geometry of triangles, as distinguished from a geometry of circles, or a separate application of the arithmetics of addition and subtraction; but made one help out the other as he best could.”

Augustus De Morgan (1806–1871) British mathematician, philosopher and university teacher (1806-1871)

Advertisement, p.4
The Differential and Integral Calculus (1836)

Dreams , Way , Help , Drawing

“I now saw, that a science is either deductive or experimental, according as, in the province it deals with, the effects of causes when conjoined, are or are not the sums of the effects which the same causes produce when separate. It followed that politics must be a deductive science. It thus appeared, that both Macaulay and my father were wrong; the one in assimilating the method of philosophising in politics to the purely experimental method of chemistry; while the other, though right in adopting a deductive method, had made a wrong selection of one, having taken as the type of deduction, not the appropriate process, that of the deductive branches of natural philosophy, but the inappropriate one of pure geometry, which, not being a science of causation at all, does not require or admit of any summing-up of effects.”

John Stuart Mill book Autobiography

Source: Autobiography (1873)
Source: https://archive.org/details/autobiography01mill/page/160/mode/1up pp. 160-161

Nature , Appearance , Science

“From Pythagoras to Boethius, when pure mathematics consisted of arithmetic and geometry while applied mathematics consisted of music and astronomy, mathematics could be characterized as the deductive study of 'such abstractions as quantities and their consequences, namely figures and so forth' (Acquinas ca. 1260). But since the emergence of abstract algebra it has become increasingly difficult to formulate a definition to cover the whole of the rich, complex and expanding domain of mathematics.”

George Frederick James Temple (1901–1992) British mathematician

100 Years of Mathematics: a Personal Viewpoint (1981)

Music , Mathematics , Study

“In 1945 I really believed that by the year 1952 no American could hear the name of Roosevelt without a shudder or utter it without a curse. You see; I was wrong. I was right about the inevitability of exposure. Like the bodies of the Polish officers who were butchered in Katyn Forest by the Bolsheviks (as we knew at the time), many of the Roosevelt regime's secret crimes were exposed to the light of day. The exposures were neither so rapid or so complete as I anticipated, but their aggregate is far more than should have been needed for the anticipated reaction. Only about 80 per cent of the secret of Pearl Harbor has thus far become known, but that 80 per cent should in itself be enough to nauseate a healthy man. Of course I do not know, and I may not even suspect, the full extent of the treason of that incredible administration. But I should guess that at least half of it has been disclosed in print somewhere: not necessarily in well-known sources, but in books and articles in various languages, including publications that the international conspiracy tries to keep from the public, and not necessarily in the form of direct testimony, but at least in the form of evidence from which any thinking man can draw the proper and inescapable deductions. The information is there for those who will seek it, and enough of it is fairly well known, fairly widely known, especially the Pearl Harbor story, to suggest to anyone seriously interested in the preservation of his country that he should learn more. But the reaction never occurred. And even today the commonly used six-cent postage stamp bears the bloated and sneering visage of the Great War Criminal, and one hears little protest from the public.”

Revilo P. Oliver (1908–1994) American philologist

"What We Owe Our Parasites", speech (June 1968); Free Speech magazine (October and November 1995)
1960s

War , Secret , Books , Thinking

“It saddens me to see the entrepreneurial world in Brazil, because it's a misfortune to be a boss in our country, with so many labor laws. […] Between a man and a young woman, what will the entrepreneur think? 'Damn, this woman's got a ring on her finger, she'll be pregnant soon, she'll be on maternity leave for six months…' […] Who's going to pay the bill? The employer. In the end it's deducted from social security but he says "the work rhythm is broken. And when she returns, she'll take a month-long vacation. In the end, she works five months in one year." […] I'm a liberal. If I want to hire you at my company paying you R$ 2,000.00 a month and Ms. Mary paying her R$ 1,500.00, and if Ms. Mary doesn't want to earn that amount, she must look for another job! If you think you also are not earning so much, look for another job. It is I who am paying you; I am the boss.”

Jair Bolsonaro (1955) Brazilian president elect

In an interview with Zero Hora newspaper https://gauchazh.clicrbs.com.br/politica/noticia/2014/12/bolsonaro-diz-que-nao-teme-processos-e-faz-nova-ofensa-nao-merece-ser-estuprada-porque-e-muito-feia-cjkf8rj3x00cc01pi3kz6nu2e.html on 10 December 2014. Brazil presidential candidate Bolsonaro's most controversial quotes https://www.yahoo.com/news/brazil-presidential-candidate-bolsonaros-most-controversial-quotes-012652084.html. Yahoo!, 29 September 2018.

World , Law , Thinking , Maternity

“[The mathematical character of Descartes' physics lies in its methodological nature, namely, the] axiomatic structure of the whole system, in the establishment of indubitable foundations and the deduction of the phenomena.”

Eduard Jan Dijksterhuis (1892–1965) Dutch historian

Source: The mechanization of the world picture, 1961, p. 414; as cited in: ‎Marleen Rozemond (2009), Descartes's Dualism. p. 235

Mathematics , Nature

“Another feature of Alexandrian algebra is the absence of any explicit deductive structure. The various types of numbers… were not defined. Nor was there any axiomatic basis on which a deductive structure could be erected. The work of Heron, Nichomachus, and Diophantus, and of Archimedes as far as his arithmetic is concerned, reads like the procedural texts of the Egyptians and Babylonians… The deductive, orderly proof of Euclid and Apollonius, and of Archimedes' geometry is gone. The problems are inductive in spirit, in that they show methods for concrete problems that presumably apply to general classes whose extent is not specified. In view of the fact that as a consequence of the work of the classical Greeks mathematical results were supposed to be derived deductively from an explicit axiomatic basis, the emergence of an independent arithmetic and algebra with no logical structure of its own raised what became one of the great problems of the history of mathematics. This approach to arithmetic and algebra is the clearest indication of the Egyptian and Babylonian influences… Though the Alexandrian Greek algebraists did not seem to be concerned about this deficiency… it did trouble deeply the European mathematicians.”

Morris Kline (1908–1992) American mathematician

Source: Mathematical Thought from Ancient to Modern Times (1972), p.144

History , Mathematics , Problem , Reading

“It is actually impossible in theory to determine exactly what the hidden mechanism is without opening the box, since there are always many different mechanisms with identical behavior. Quite apart from this, analysis is more difficult than invention in the sense in which, generally, induction takes more time to perform than deduction: in induction one has to search for the way, whereas in deduction one follows a straightforward path.”

Valentino Braitenberg (1926–2011) Italian-Austrian neuroscientist

Source: Vehicles: Experiments in Synthetic Psychology (1984), p. 20 as cited in: Yll Haxhimusa (2006) The Structurally Optimal Dual Graph Pyramid and Its Application in Image Partitioning. p. 149

Way , Behavior , Search , Sense

“The party first makes a correct return to the best of his ability but is considered to be a simpleton and fool. His word or explanations are not accepted or are looked upon with suspicion by the Assessing Authority, who may be his inferior perhaps in status. Arbitrary and unwarranted deductions are made and the poor party is unfairly over-assessed without hope of getting any proper relief. If he appeals the Superior Officer supports his subordinate and it may take years, expense and the ruling of a High Court to see that Justice is done. So what can be the result in such a case? At the next encounter you may be sure the party will be ready to match his skill against his instigator and to throw as many red herrings as he can on the trail. It will now require all the subtlety, knowledge and acumen of the authorities to arrive at the proper conclusion, and failure is generally the result. Lakhs of rupees of Income Tax dues remain outstanding and years of litigation follow and eventually the Tax is time-barred and non recoverable.”

Peter de Noronha (1897–1970) Indian businessman

The Pageant of Life (1964), On Income Tax

Justice , Hope , Fools , Failure

“If I married him,
I would not dare to call my soul my own,
Which so he had bought and paid for: every thought
And every heart-beat down there in the bill,–
Not one found honestly deductible
From any use that pleased him!”

Elizabeth Barrett Browning (1806–1861) English poet, author

Bk. II, l. 785-790.
Aurora Leigh http://digital.library.upenn.edu/women/barrett/aurora/aurora.html (1857)

Soul , Heart

“Robert [Grosseteste] became much interested in science and scientific method … He was conscious of the dual approach by means of induction and deduction (resolution and composition); i. e., from the empirical knowledge one proceeds to probable general principles, and from these as premises one them derives conclusions which constitute verifications or falsifications of the principles. This approach to science was not that far removed from Aristotle …”

Carl B. Boyer (1906–1976) American mathematician

Source: The Rainbow: From Myth to Mathematics (1959), p. 88

Knowledge , Science

“The functional validity of a working hypothesis is not a priori certain, because often it is initially based on intuition. However, logical deductions from such a hypothesis provide expectations (so called prognoses) as to the circumstances under which certain phenomena will appear in nature. Such a postulate or working hypothesis can then be substantiated by additional observations or by experiments especially arranged to test details. The value of the hypothesis is strengthened if the observed facts fit the expectation within the limits of permissible error.”

Reinout Willem van Bemmelen (1904–1983) Dutch geologist

Source: "The Scientific Character of Geology," 1961, p. 454; As cited in: Alberta Research Council, ‎Research Council of Alberta (1964), Bulletin - Alberta Research Council. Vol. 15-17, p. 31

Error , Nature , Appearance

“Knowledge about things beyond our immediate environment may be acquired through deduction, if the initial premises are believed to be correct.”

Nayef Al-Rodhan (1959) philosopher, neuroscientist, geostrategist, and author

Source: Sustainable History and the Dignity of Man (2009), p.108

Knowledge

“But much more vicious than these cases is the majority of foreign correspondents who never have to be placed against the wall, who are never told what to write and how to write it, but who know from contact with the great minds of the press lords or from the simple deduction that the bosses are in big business and the news must be slanted accordingly, or from the general intangible atmosphere which prevails everywhere, what they can do and what they must never do. The most stupid boast in the history of present-day journalism is that of the writer who says, "I have never been given orders; I am free to do as I like."”

George Seldes (1890–1995) American journalist

Lords of the Press

Stupidity , History , Business

“I have indeed lived nominally fifty years, but deduct out of them the hours which I have lived to other people, and not to myself, and you will find me still a young fellow. For that is the only true time, which a man can properly call his own, that which he has all to himself; the rest, though in some sense he may be said to live it, is other people’s time, not his. The remnant of my poor days, long or short, is at least multiplied for me three-fold. My ten next years, if I stretch so far, will be as long as any preceding thirty.”

Charles Lamb Last Essays of Elia

“The superannuated man”
Last Essays of Elia (1833)

People , Sense , Time

“Hippocrates himself is an example of the concurrent study of the two departments. On the one hand, he was the first of the Greeks who is known to have compiled a book of Elements. This book, we may be sure, contained in particular the most important propositions about the circle included in Euclid, Book III. But a much more important proposition is attributed to Hippocrates; he is said to have been the first to prove that circles are to one another as the squares on their diameters (= Eucl. XII., 2) with the deduction that similar segments of circles are to one another as the squares on their bases. These propositions were used by him in his tract on the squaring of lunes, which was intended to lead up to the squaring of the circle. The latter problem is one which must have exercised practical geometers from time immemorial. Anaxagoras for instance is said to have worked at the problem while in prison.”

Thomas Little Heath (1861–1940) British civil servant and academic

p, 125
Achimedes (1920)

Books , Exercises , Problem , Study

“Pure mathematics is a collection of hypothetical, deductive theories, each consisting of a definite system of primitive, undefined, concepts or symbols and primitive, unproved, but self-consistent assumptions (commonly called axioms) together with their logically deducible consequences following by rigidly deductive processes without appeal to intuition.”

Joshua Girling Fitch (1824–1903) British educationalist

The Fourth Dimension simply Explained. (New York, 1910), p. 58. Reported in Moritz (1914); Also cited in: Howard Eves (2012), Foundations and Fundamental Concepts of Mathematics, p. 167

Mathematics

“What mathematics, therefore are expected to do for the advanced student at the university, Arithmetic, if taught demonstratively, is capable of doing for the children even of the humblest school. It furnishes training in reasoning, and particularly in deductive reasoning. It is a discipline in closeness and continuity of thought. It reveals the nature of fallacies, and refuses to avail itself of unverified assumptions. It is the one department of school-study in which the sceptical and inquisitive spirit has the most legitimate scope; in which authority goes for nothing. In other departments of instruction you have a right to ask for the scholar’s confidence, and to expect many things to be received on your testimony with the understanding that they will be explained and verified afterwards. But here you are justified in saying to your pupil “Believe nothing which you cannot understand. Take nothing for granted.” In short, the proper office of arithmetic is to serve as elementary 268 training in logic. All through your work as teachers you will bear in mind the fundamental difference between knowing and thinking; and will feel how much more important relatively to the health of the intellectual life the habit of thinking is than the power of knowing, or even facility of achieving visible results. But here this principle has special significance. It is by Arithmetic more than by any other subject in the school course that the art of thinking—consecutively, closely, logically—can be effectually taught.”

Joshua Girling Fitch (1824–1903) British educationalist

Source: Lectures on Teaching, (1906), pp. 292-293.

Life , Children , Health , School

“I began studying philosophy and economics about the same time. The similarity of the two disciplines struck me at once. I found no difficulty in grasping the differences between the great philosophical systems as they were presented by our textbooks and our teachers. Economic theory was easier still. Indeed, I thought the successive systems of economics were rather crude affairs compared with the subtleties of the metaphysicians. Having run the gamut from Plato to T. H. Green (as undergraduates do) I felt the gamut from Quesnay to Marshall was a minor theme. The technical part of the theory was easy. Give me premises and I could spin speculations by the yard. Also I knew that my 'deductions' were futile…
Meanwhile I was finding something really interesting in philosophy and in economics. John Dewey was giving courses under all sorts of titles and every one of them dealt with the same problem — how we think… And, if one wanted to try his own hand at constructive theorizing, Dewey's notion pointed the way. It is a misconception to suppose that consumers guide their course by ratiocination—they don't think except under stress. There is no way of deducing from certain principles what they will do, just because their behavior is not itself rational. One has to find out what they do. That is a matter of observation, which the economic theorists had taken all too lightly. Economic theory became a fascinating subject—the orthodox types particularly — when one began to take the mental operations of the theorists as the problem…
Of course Veblen fitted perfectly into this set of notions. What drew me to him was his artistic side… There was a man who really could play with ideas! If one wanted to indulge in the game of spinning theories who could match his skill and humor? But if anything were needed to convince me that the standard procedure of orthodox economics could meet no scientific tests, it was that Veblen got nothing more certain by his dazzling performances with another set of premises…
William Hill set me a course paper on 'Wool Growing and the Tariff.”

Wesley Clair Mitchell (1874–1948) American statistician

I read a lot of the tariff speeches and got a new sidelight on the uses to which economic theory is adapted, and the ease with which it is brushed aside on occasion. Also I wanted to find out what really had happened to wool growers as a result of protection. The obvious thing to do was to collect and analyze the statistical data... That was my first 'investigation'.
Wesley Clair Mitchell in letter to John Maurice Clark, August 9, 1928. Originally printed in Methods in Social Science, ed. Stuart Rice; Cited in: Arthur F. Burns (1965, 65-66)

Way , Behavior , Game , Idea

“They already expect you to just give a check to tax-deductible charity organization.”

Bob Dylan (1941) American singer-songwriter, musician, author, and artist

Song lyrics, Highway 61 Revisited (1965), Ballad of a Thin Man

“In every science, after having analysed the ideas, expressing the more complicated by means of the more simple, one finds a certain number that cannot be reduced among them, and that one can define no further. These are the primitive ideas of the science; it is necessary to acquire them through experience, or through induction; it is impossible to explain them by deduction.”

Giuseppe Peano (1858–1932) Italian mathematician

Notations de Logique Mathématique (1894), p. 173, as quoted in "The Mathematical Philosophy of Giuseppe Peano" by Hubert C. Kennedy, in Philosophy of Science Vol. 30, No. 3 (July 1963)

Idea , Science

“I cannot see why it is necessary that every deduction from algebra should be bound to certain conventions incident to an earlier stage of mathematical learning, even supposing them to have been consistently used up to the point in question. I should not care if any one thought this treatise unalgebraical, but should only ask whether the premises were admissible and the conclusions logical.”

Augustus De Morgan (1806–1871) British mathematician, philosopher and university teacher (1806-1871)

Advertisement, p.3
The Differential and Integral Calculus (1836)

Mathematics , Question , Learning

“If a lack of empirical foundations is a defect of the theory of logical probability, it is also a defect of deductive logic.”

David Stove (1927–1994) Australian philosopher

The Rationality of Induction, Oxford: Clarendon, 1986. Page 176, last paragraph.

“I agree with you to the letter in all you say about Ireland. There is no doubt that the land question (coupled with the Church Establishment) is at the root of the evil. And here let me say that I go heartily with you in the determination to attack the land monopoly root and branch both here and in Ireland and Scotland…. Wherever the deductions of political economy lead I am prepared to follow. By the way, have you had time to read Bastiat's partly posthumous volume, 'Les Harmonies Economiques'? If not, do so; it will require a studious perusal, but will repay it. He has breathed a soul into the dry bones of political economy, and has vindicated his favourite science from the charge of inhumanity with all the fervour of a religious devotee.”

Richard Cobden (1804–1865) English manufacturer and Radical and Liberal statesman

Letter to John Bright (1 October 1851), quoted in John Morley, The Life of Richard Cobden (London: T. Fisher Unwin, 1905), p. 561.
1850s

Way , Soul , Question , Science

“How much do you think it costs to go to college? Most people are likely to answer by adding together their expenditures on tuition, room and board, books, and the like, and then deducting any scholarship funds they may receive. Suppose that amount comes to $15,000.
Economists keep score differently. They first want to know how much you would be earning if you were not attending college. Suppose that salary is $20,000 per year. This may seem irrelevant, but because you give up these earnings by attending college, they must be added to your tuition bill. You have that much less income because of your education. On the other side of the ledger, economists would not count all of the university’s bill for room and board as part of the costs of your education. They would want to know how much more it costs you to live at school rather than at home. Economists would count only these extra costs as an educational expense because you would have incurred these costs whether or not you attend college. On balance, college is probably costing you much more than you think. And, as we will see later, taking opportunity cost into account in any personal planning will help you to make more rational decisions.”

William J. Baumol (1922–2017) American economist

William Baumol and Alan Blinder, Economics: Principles and Policy (2011), Ch. 1 : What is Economics?

People , Books , Education , School

“29 million people have no health insurance today in America. We pay, by far, the highest prices in the world for prescription drugs. One out of five Americans can't even afford the prescriptions their doctors are writing. Millions of people have high deductibles and co-payments. I don't know what economists Secretary Clinton is talking to, but what I have said, is that the family right in the middle of the economy would pay $500 dollars more in taxes, and get a reduction in their healthcare costs of $5,000 dollars. In my view healthcare is a right of all people, not a privilege, and I will fight for that.”

Bernie Sanders (1941) American politician, senator for Vermont

2010s, 2016, Democratic Presidential Debate in Milwaukee, Wisconsin (11 February 2016)

People , Health , World , Family

“The facts drawn from an experience of more than twenty years enable us to make certain deductions with respect to the study of the Negro. Only one Negro out of every ten thousand is interested in the effort to set forth what his race has thought and felt and attempted and accomplished that it may not become a negligible factor in the thought of the world. By traditions and education, however, the large majority of Negroes have become interested in the history and status of other races, and they spend millions annually to promote such knowledge. Along with this sum, of course, should be considered the large amount paid for devices in trying not to be Negroes.”

Carter G. Woodson book The Mis-Education of the Negro

Source: The Mis-Education of the Negro (1933), Chapter XVIII: The Study of the Negro

World , Education , History , Knowledge

“I presume that few who have paid any attention to the history of the Mathematical Analysis, will doubt that it has been developed in a certain order, or that that order has been, to a great extent, necessary -- being determined, either by steps of logical deduction, or by the successive introduction of new ideas and conceptions, when the time for their evolution had arrived.”

George Boole (1815–1864) English mathematician, philosopher and logician

Source: 1850s, A treatise on differential equations (1859), p. v; cited in: Quotations by George Boole http://www-history.mcs.st-and.ac.uk/Quotations/Boole.html, MacTutor History of Mathematics, August 2010.

History , Mathematics , Idea , Time

“I cannot forbear adding to these reasonings an observation, which may, perhaps, be found of some importance. In every system of morality, which I have hitherto met with, I have always remarked, that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when of a sudden I am surprized to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, it is necessary that it should be observed and explained; and at the same time that a reason should be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it. But as authors do not commonly use this precaution, I shall presume to recommend it to the readers; and am persuaded, that this small attention would subvert all the vulgar systems of morality, and let us see, that the distinction of vice and virtue is not founded merely on the relations of objects, nor is perceived by reason.”

David Hume book A Treatise of Human Nature

Part 1, Section 1
A Treatise of Human Nature (1739-40), Book 3: Of morals

God , Way , Change , Time

“Thinking is seeing," said he one day, carried away by some objection raised as to the first principles of our organisation."Every human science is based on deduction, which is a slow process of seeing by which we work up from the effect to the cause; or, in a wider sense, all poetry like every work of art proceeds from a swift vision of things.”

Honoré de Balzac (1799–1850) French writer

Penser, c'est voir! me dit-il un jour emporté par une de nos objections sur le principe de notre organisation. Toute science humaine repose sur la déduction, qui est une vision lente par laquelle on descend de la cause à l'effet, par laquelle on remonte de l'effet à la cause; ou, dans une plus large expression, toute poésie comme toute oeuvre d'art procède d'une rapide vision des choses.
Honoré de Balzac, Louis Lambert http://fr.wikisource.org/wiki/Louis_Lambert (1832), translated by Clara Bell

Art , Thinking , Sense , Science

“Suppose the reasoning centers of the brain can get their hands on the mechanisms that plop shapes into the array and that read their locations out of it. Those reasoning demons can exploit the geometry of the array as a surrogate for keeping certain logical constraints in mind. Wealth, like location on a line, is transitive: if A is richer than B, and B is richer than C, then A is richer than C. By using location in an image to symbolize wealth, the thinker takes advantage of the transitivity of location built into the array, and does not have to enter it into a chain of deductive steps. The problem becomes a matter of plop down and look up. It is a fine example of how the form of a mental representation determines what is easy or hard to think.”

Steven Pinker book How the Mind Works

Source: How the Mind Works (1997), p. 291

Problem , Thinking , Reading , Wealth

“No book is fairly judged till it is read twice, and at distant periods. It is curious to note the variation of taste in ourselves. I can remember I devoured the story keenly, dwelt on all that partook of sentiment, and never questioned the depth of any remark. I now find that I take chief interest in what brings out character. I enter more into the humourous, and am every now and then tempted to analyse the truth of a deduction. I think more over what I am reading, and delight more in connecting the world of fiction with that of reality.”

Letitia Elizabeth Landon (1802–1838) English poet and novelist

No.17. The Monastery — MARY AVENEL.
Literary Remains

Truth , Books , World , Question

“Aristotle writes that persuasion is based on three things: the ethos, or personal character of the speaker; the pathos, or getting the audience into the right kind of emotional receptivity; and the logos, or the argument itself, carried out by abbreviated syllogisms, or something like deductive syllogisms, and by the use of example.”

Randal Marlin (1938) Canadian academic

Source: Propaganda & The Ethics Of Persuasion (2002), Chapter Two, History Of Propaganda, p. 47

Personality

“There is no reason why the profoundest thoughts should not make easy and exciting reading. A profound thought is an exciting thing — as exciting as a detective's deductions or hunches. The simpler the words in which a thought is expressed the more stimulating its effect.”

Eric Hoffer (1898–1983) American philosopher

Entry (1950)
Eric Hoffer and the Art of the Notebook (2005)

Reading

“… when the empire dissolved… the people of Britain suffered from a kind of vertigo: they could not believe that they were standing upright, and reached out for something to clutch. It seemed axiomatic that economically, as well as politically, they must be part of something bigger, though the deduction was as unfounded as the premise. So some cried: 'Revive the Commonwealth'. And others cried: 'Let's go in with America into a North Atlantic Free Trade Area'. Yet others again cried: 'We have to go into Europe: there's no real alternative'. In a sense they were right: there is no alternative grouping. In a more important sense they were wrong: there is no need for joining anything. A Britain which is ready to exchange goods, services and capital as freely as it can with the rest of the world is neither isolated nor isolationist. It is not, in the sneering phrases of Chamberlain's day, 'Little England'… The Community is not a free trade area, which is what Britain, with a correct instinct, tried vainly to convert it into, or combine it into, in 1957-60. For long afterwards indeed many Britons continued to cherish the delusion that it really was a glorified free trade area and would turn out to be nothing more. On the contrary the Community is, what its name declares, a prospective economic unit. But an economic unit is not defined by economics – there are no natural economic units – it is defined by politics. What we call an economic unit is really a political unit viewed in its economic aspect: the unit is political.”

Enoch Powell (1912–1998) British politician

Speech in Frankfurt (29 March 1971), from The Common Market: The Case Against (Elliot Right Way Books, 1971), pp. 76-77.
1970s

People , World , Communication , Nature

“In the original discovery of a proposition of practical utility, by deduction from general principles and from experimental data, a complex algebraical investigation is often not merely useful, but indispensable; but in expounding such a proposition as a part of practical science, and applying it to practical purposes, simplicity is of the importance:—and… the more thoroughly a scientific man has studied higher mathematics, the more fully does he become aware of this truth—and… the better qualified does he become to free the exposition and application of principles from mathematical intricacy.”

William John Macquorn Rankine (1820–1872) civil engineer

p, 125
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Truth , Mathematics , Study , Science

“The two great conceptual revolutions of twentieth-century science, the overturning of classical physics by Werner Heisenberg and the overturning of the foundations of mathematics by Kurt Gödel, occurred within six years of each other within the narrow boundaries of German-speaking Europe. … A study of the historical background of German intellectual life in the 1920s reveals strong links between them. Physicists and mathematicians were exposed simultaneously to external influences that pushed them along parallel paths. … Two people who came early and strongly under the influence of Spengler's philosophy were the mathematician Hermann Weyl and the physicist Erwin Schrödinger. … Weyl and Schrödinger agreed with Spengler that the coming revolution would sweep away the principle of physical causality. The erstwhile revolutionaries David Hilbert and Albert Einstein found themselves in the unaccustomed role of defenders of the status quo, Hilbert defending the primacy of formal logic in the foundations of mathematics, Einstein defending the primacy of causality in physics. In the short run, Hilbert and Einstein were defeated and the Spenglerian ideology of revolution triumphed, both in physics and in mathematics. Heisenberg discovered the true limits of causality in atomic processes, and Gödel discovered the limits of formal deduction and proof in mathematics. And, as often happens in the history of intellectual revolutions, the achievement of revolutionary goals destroyed the revolutionary ideology that gave them birth. The visions of Spengler, having served their purpose, rapidly became irrelevant.”

Freeman Dyson (1923) theoretical physicist and mathematician

The Scientist As Rebel (2006)

Life , People , History , Mathematics

“Among the names of those who have led the great advance of the industrial arts during the past thirty years, that of Frederick Winslow Taylor will hold an increasingly high place. Others have led in electrical development, in the steel industry, in industrial chemistry, in railroad equipment, in the textile arts, and in many other fields, but he has been the creator of a new science, which underlies and will benefit all of these others by greatly increasing their efficiency and augmenting their productivity. In addition, he has literally forged a new tool for the metal trades, which has doubled, or even trebled, the productive capacity of nearly all metal-cutting machines. Either achievement would entitle him to high rank among the notable men of his day; — the two combined give him an assured place among the world's leaders in the industrial arts.
Others without number have been organizers of industry and commerce, each working out, with greater or less success, the solution of his own problems, but none perceiving that many of these problems involved common factors and thus implied the opportunity and the need of an organized science. Mr. Taylor was the first to grasp this fact and to perceive that in this field, as in the physical sciences, the Baconian system could be applied, that a practical science could be created by following the three principles of that system, viz.: the correct and complete observation oi facts, the intelligent and unbiased analysis of such facts, and the formulating of laws by deduction from the results so reached. Not only did he comprehend this fundamental conception and apply it; he also grasped the significance and possibilities of the problem so fully that his codification of the fundamental principles of the system he founded is practically complete and will be a lasting monument to its founder.”

Henry R. Towne (1844–1924) American engineer

Henry R. Towne, in: Frank Barkley Copley, Frederick W. Taylor, father of scientific management https://archive.org/stream/frederickwtaylor01copl, 1923. p. xii.

Men , World , Law , Art

“I have tried to make clear in this brief sketch of the nature of deductively formulated theories, at least as they occur in economics, that, although their origin lies in common observation and introspection, nevertheless they are capable of a purely mathematical development through the exact statement of a of a set of postulates which, however, since they must inevitably contain assumptions about human behaviour, require to be tested by reference to actual events.”

Richard Stone (1913–1991) British economist, Nobel Memorial Prize winner

Source: The Role of Measurement in Economics. 1951, p. 14-15

Mathematics , Nature

“During all those years of experimentation and research, I never once made a discovery. All my work was deductive, and the results I achieved were those of invention, pure and simple.”

Thomas Edison (1847–1931) American inventor and businessman

On his years of research in developing the electric light bulb, as quoted in "Talks with Edison" by George Parsons Lathrop in Harper's magazine, Vol. 80 (February 1890), p. 425.
Context: During all those years of experimentation and research, I never once made a discovery. All my work was deductive, and the results I achieved were those of invention, pure and simple. I would construct a theory and work on its lines until I found it was untenable. Then it would be discarded at once and another theory evolved. This was the only possible way for me to work out the problem. … I speak without exaggeration when I say that I have constructed 3,000 different theories in connection with the electric light, each one of them reasonable and apparently likely to be true. Yet only in two cases did my experiments prove the truth of my theory. My chief difficulty was in constructing the carbon filament.... Every quarter of the globe was ransacked by my agents, and all sorts of the queerest materials used, until finally the shred of bamboo, now utilized by us, was settled upon.

“One cannot help but be struck by the diversity that characterizes efforts to study the management process. If it is true that psychologists like to study personality traits in terms of a person's reactions to objects and events, they could not choose a better stimulus than management science. Some feel it is a technique, some feel it is a branch of mathematics, or of mathematical economics, or of the "behavioral sciences," or of consultation services, or just so much nonsense. Some feel it is for management (vs. labor), some feel it ought to be for the good of mankind — or for the good of underpaid professors.
But this diversity of attitude, which is really characteristic of all fields of endeavor, is matched by another and more serious kind of diversity. In the management sciences, we have become used to talking about game theory, inventory theory, waiting line theory. What we mean by "theory" in this context is that if certain assumptions are valid, then such-and-such conclusions follow. Thus inventory theory is not a set of statements that predict how inventories will behave, or even how they should behave in actual situations, but is rather a deductive system which becomes useful if the assumptions happen to hold. The diversity of attitude on this point is reflected in two opposing points of view: that the important problems of management science are theoretical, and that the important problems are factual.”

C. West Churchman (1913–2004) American philosopher and systems scientist

quote in: Fremont A. Shull (ed.), Selected readings in management https://archive.org/stream/selectedreadings00shul#page/n13/mode/2up, , 1957. p. 7-8
1940s - 1950s, "Management Science — Fact or Theory?" 1956

Behavior , Feeling , Game , Mathematics

“Einstein's theory has the very highest degree of æsthetic merit: every lover of the beautiful must wish it to be true. It gives a vast unified survey of the operations of nature, with a technical simplicity in the critical assumptions which makes the wealth of deductions astonishing. It is a case of an advance arrived at by pure theory: the whole effect of Einstein's work is to make physics more philosophical (in a good sense), and to restore some of that intellectual unity which belonged to the great scientific systems of the seventeenth and eighteenth centuries, but which was lost through increasing specialization and the overwhelming mass of detailed knowledge. In some ways our age is not a good one to live in, but for those who are interested in physics there are great compensations.”

Hendrik Lorentz (1853–1928) Dutch physicist

p, 125
Theory of Relativity: A Concise Statement (1920)

Age , Beauty , Way , Lovers

“The type of rationality we assume in economics — perfect, logical, deductive rationality — is extremely useful in generating solutions to theoretical problems. But it demands much of human behavior — much more in fact than it can usually deliver. If we were to imagine the vast collection of decision problems economic agents might conceivably deal with as a sea or an ocean, with the easier problems on top and more complicated ones at increasing depth, then deductive rationality would describe human behavior accurately only within a few feet of the surface. For example, the game Tic-Tac-Toe is simple, and we can readily find a perfectly rational, minimax solution to it. But we do not find rational “solutions” at the depth of Checkers; and certainly not at the still modest depths of Chess and Go.”

W. Brian Arthur (1946) American economist

Source: Inductive Reasoning and Bounded Rationality (The El Farol Problem) (1994), p. 1

Behavior , Imagination , Game , Problem

“ACCORDING TO the numerous deductions and conclusions made by me during experimental elucidations concerning the productivity of the perception by contemporary people of new impressions from what is heard and read, and also according to the thought of one of the sayings of popular wisdom I have just remembered, handed down to our days from very ancient times, which declares: “Any prayer may be heard by the Higher Powers and a corresponding answer obtained only if it is uttered thrice:
:Firstly—for the welfare or the peace of the souls of one’s parents.
:Secondly—for the welfare of one’s neighbor.
:And only thirdly—for oneself personally.”

G. I. Gurdjieff (1866–1949) influential spiritual teacher, Armenian philosopher, composer and writer

"Friendly Advice [Written impromptu by the author on delivering this book, already prepared for publication, to the printer" (1949)
All and Everything: Beelzebub's Tales to His Grandson (1950)

Wisdom , People , Peace , Soul

“James Baker was the only leader in America who had the guts to stand up and act against Israel's malignant disease: the settlements. When he was the Secretary of State, he simply informed the Israeli government that he would deduct the sums expended on the settlements from the money Israel was getting from the US. Threatened and made good on his threat. Baker thus confronted the "pro-Israeli" lobby in the US, both the Jewish and the Christian. Such courage is rare in the United States, as it is rare in Israel.”

Uri Avnery (1923–2018) Israeli writer

Baker's Cake (December 9, 2006)

Money , Disease , Courage

“All science is full of statements where you put the best face on your ignorance, where you say: true enough, we know awfully little about this, but more or less irrespective of the stuff we don't know about, we can make certain useful deductions.”

Hermann Bondi (1919–2005) British mathematician and cosmologist

Hermann Bondi, Assumption and Myth in Physical Theory, (1967) p. 11

Science

“We are apt… to forget that the moral force of Christianity was usually only one factor in producing such a change as the abolition of slavery or piracy, and that over against the benign influences of the Church must be set the malign and divisive influences which she created by persecuting zeal, intellectual intolerance, or religious wars. In short, we must soberly face the fact that a good many deductions have to be made from the popular panegyrics, and that the Church has not accomplished all that is often claimed for her.”

Walter Rauschenbusch (1861–1918) United States Baptist theologian

Source: Christianity and the Social Crisis (1907), Ch.4 Why Has Christianity Never Undertaken the Work of Social Reconstruction?, p. 149

War , Change , Forgetting

“The feminist-only funding leads to studies that misinform the nation that a divorced mother is economically more hurt than a divorced man, so judges feel a mandate to make his future income hers, and legislatures feel fine about refusing to make his mother subsidy payments tax deductible even as she pays no taxes on the money received. And all this perpetuates the belief that he earns more money….”

Warren Farrell (1943) author, spokesperson, expert witness, political candidate

Source: Father and Child Reunion (2001), p. 240.

Money , Feeling , Study , Future

“• Special Provision on the Provision and Maintenance of Basic Educational Facilities was amended to reflect changes in the distribution of the appropriations and the inclusion of an amount for the annual payment of school buildings constructed by the NHA. Likewise, the said provision also allows the DepEd to deduct a 0.5% engineering and administrative overhead (EAO) on the project cost.”

Francis Escudero (1969) Filipino politician

2014, Speech: Sponsorship Speech for the FY 2015 National Budget

Education , School , Change

“Whether sociology can ever become a full-fledged "science" (a description of a class of events predictable on the basis of deductions from a constant rationale) depends on whether the terms which sociologists employ to describe events can be analyzed into quantifiable observables.”

Anatol Rapoport (1911–2007) Russian-born American mathematical psychologist

Anatol Rapoport, "Outline of a probabilistic approach to animal sociology: I." The Bulletin of mathematical biophysics 11.3 (1949): p 183
1940s

Science , Dependency

“Special pleading that the standards of science should be lessened to admit explanations with no falsifiable consequences, in order to keep alive a bold speculative idea, should be strongly resisted. …ultimately science is not interested in what might be true, it is interested only in what can be convincingly demonstrated by deductions from observational evidence.”

Lee Smolin (1955) American cosmologist

"A perspective on the landscape problem" arXiv (Feb 15, 2012)

Idea , Science

“I am not keeping back facts. Every fact that I know is in your possession. You can draw your own deductions from them.”

Agatha Christie book The Mysterious Affair at Styles

Hercule Poirot
The Mysterious Affair at Styles (1920)

Drawing

“So we have these wide principles which sweep across all the different laws, and if one takes too seriously its derivations, and feels that this is only valid because this [assumed more fundamental principle] is valid, you cannot understand the interconnections of the different branches of physics. Some day, when physics is complete, then maybe with this kind of argument we'll know all the laws, then we can start with some axioms (and no doubt somebody will figure out a particular way of doing it) and then all the deductions will be made. But while we don't know all the laws, we can use some to make guesses at theorems which extend beyond the proof.”

Richard Feynman book The Character of Physical Law

Source: The Character of Physical Law (1965), chapter 2, “The Relation of Mathematics to Physics”

Law , Way , Feeling , Understanding

“Science focuses on the study of the natural world. It seeks to describe what exists. Focusing on problem finding, it studies and describes problems in its various domains. The humanities focus on understanding and discussing the human experience. In design, we focus on finding solutions and creating things and systems of value that do not yet exist.
The methods of science include controlled experiments, classification, pattern recognition, analysis, and deduction. In the humanities we apply analogy, metaphor, criticism, and (e)valuation. In design we devise alternatives, form patterns, synthesize, use conjecture, and model solutions. \
Science values objectivity, rationality, and neutrality. It has concern for the truth. The humanities value subjectivity, imagination, and commitment. They have a concern for justice. Design values practicality, ingenuity, creativity, and empathy. It has concerns for goodness of fit and for the impact of design on future generations.”

Béla H. Bánáthy (1919–2003) Hungarian linguist and systems scientist

Source: Designing Social Systems in a Changing World (1996), p. 34-35, as cited in Alexander Laszlo and Stanley Krippner (1992) " Systems Theories: Their Origins, Foundations, and Development http://archive.syntonyquest.org/elcTree/resourcesPDFs/SystemsTheory.pdf" In: J.S. Jordan (Ed.), Systems Theories and A Priori Aspects of Perception. Amsterdam: Elsevier Science, 1998. Ch. 3, pp. 47-74.

Truth , World , Justice , Imagination

“The larger the deductible you choose, the less insurance you are buying. Insurers want to sell insurance.”

Andrew Tobias (1947) American journalist

Source: The Invisible Bankers, Everything The Insurance Industry Never Wanted You To Know (1982), Chapter 9, Too Much Insurance, p. 155.

“In deduction the mind is under the dominion of a habit or association by virtue of which a general idea suggests in each case a corresponding reaction. This is the way the hind legs of a frog separated from the rest of the body, reason, when you pinch them. It is the lowest form of psychical manifestation.”

Charles Sanders Peirce (1839–1914) American philosopher, logician, mathematician, and scientist

The Law of Mind (1892)

Way , Idea

“"I exist" does not follow from "there is a thought now." The fact that a thought occurs at a given moment does not entail that any other thought has occurred at any other moment, still less that there has occurred a series of thoughts sufficient to constitute a single self. As Hume conclusively showed, no one event intrinsically points to any other. We infer the existence of events which we are not actually observing, with the help of general principle. But these principles must be obtained inductively. By mere deduction from what is immediately given we cannot advance a single step beyond. And, consequently, any attempt to base a deductive system on propositions which describe what is immediately given is bound to be a failure.”

Alfred Jules Ayer book Language, Truth, and Logic

Source: Language, Truth, and Logic (1936), p. 47.

Failure , Help

“The rule is derived inductively from experience, therefore does not have any inner necessity, is always valid only for special cases and can anytime be refuted by opposite facts. On the contrary, the law is a logical relation between conceptual constructions; it is therefore deductible from upper [übergeordnete] laws and enables the derivation of lower laws; it has as such a logical necessity in concordance with its upper premises; it is not a mere statement of probability, but has a compelling, apodictic logical value once its premises are accepted”

Ludwig von Bertalanffy (1901–1972) austrian biologist and philosopher

Source: 1920s, Kritische Theorie der Formbildung (1928, 1933), p. 91; as cited in: M. Drack, W. Apfalter, D. Pouvreau (2007) " On the making of a system theory of life: Paul A Weiss and Ludwig von Bertalanffy's conceptual connection http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2874664/". in: Q Rev Biol. 2007 December; 82(4): 349–373.

Law

“A system is said to be coherent if every fact in the system is related every other fact in the system by relations that are not merely conjunctive. A deductive system affords a good example of a coherent system.”

Susan Stebbing (1885–1943) British philosopher

As quoted in A Modern Introduction to Logic (1930), p. 198.

“Neither in deductive nor inductive reasoning can we add a tittle to our implicit knowledge, which is like that contained in an unread book or a sealed letter. …Reasoning explicates or brings to conscious possession what was before unconscious. It does not create, nor does it destroy, but it transmutes and throws the same matter into a new form.”

William Stanley Jevons (1835–1882) English economist and logician

Source: The Principles of Science: A Treatise on Logic and Scientific Method (1874) Vol. 1, p. 136

Books , Knowledge

“When you look and see what the left is trying to do in America today, progressives are trying to shutter faith, privatize it, push it out of the public square, oppress people of faith, strip their charitable deductions away from them, trying to weaken them, churches — trying to say that anybody who believes in the value of Judeo-Christian principles, as we saw in the Ninth Circuit just this week, that if you believe that — this is what the court said — that if believe that, if believe what's taught in Genesis, if you believe what's practiced Biblically and in generations since, then you are irrational. The only possible reason you could believe this, according to the Ninth Circuit, is that you are a bigot, and that you are a hater. Because you can't possibly think differently, you can't possibly think differently unless you are a bigot or a hater, cause there's no rational reason not to see marriage as the way the Ninth Circuit does. They are taking faith and crushing it. Why? Why? When you marginalize faith in America, when you remove the pillar of God-given rights, then what's left is the. What's left is a government that gives you rights. What's left are no unalienable rights. What's left is a government that will tell you who you are, what you'll do and when you'll do it. What's left, in France, became the guillotine.
Ladies and gentlemen, we're a long way from that, but if we do, and follow the path of President Obama, and his overt hostility to faith in America, then we are headed down that road.”

Rick Santorum (1958) American politician

referring to Ninth Circuit ruling unconstitutional , which banned same-sex marriage

God , Hostility , Marriage , People

“Having red several of your books, I wonder if you [ Rudolf Steiner, the German founder of anthroposophy] could find the time to read my brochure 'Le Néo-Plasticisme', which I am closing. I believe that Neo-Plasticism is the art of the foreseeable future for all true anthroposophists and theosophists. Neo-Plasticism creates harmony through the equivalence of the two extremes: the universal and the individual. The former by 'revelation', the latter by 'deduction'... It was impossible to bring about an equilibrium of relationships other than by destroying the 'form', and replacing it by a new 'universal' expressive means.”

Piet Mondrian (1872–1944) Peintre Néerlandais

Quote from Mondrian's letter to Rudolf Steiner, c. 1921-23; as cited in Abstract Painting, Michel Seuphor, Dell Publishing Co 1964, p. 83-85
1920's

Books , Art , Universe , Time

“Both induction and deduction, reasoning from the particular and the general, and back again from the universal to the specific, form the essence to scientific thinking.”

Hans Christian von Baeyer (1938) American physicist

Source: Information, The New Language of Science (2003), Chapter 16, Unpacking Information, The computer in the service of physics, p. 138

Thinking , Universe

“Lawrence O'Donnell: Mr. Cain, in fact, you were in college from 1963 to 1967, at the height of the civil rights movement, exactly when the most important demonstrations and protests were going on. You could easily, as a student at Morehouse, between 1963 and 1967, actively participated in the kinds of protests that got African Americans the rights they enjoy today. You watched from that perspective at Morehouse when you were not participating in those processes. You watch black college students from around the country and white college students from around the country come to the South and be murdered fighting for the right of African Americans. Do you regret sitting on those sidelines at that time?
Herman Cain: Lawrence, your attempt to say that I sat on the sidelines is an irrelevant comparison that you are trying to deduce from that—
Lawrence O'Donnell: It's in your book. It's in your book.
Herman Cain: Now, Lawrence, I know what's in my book. Now, let me ask you a question. Did you expect every black student and every black college in America to be out there, in the middle of every fight? The answer is no. So for you to say, why was I sitting on the sidelines, I think that that is an inaccurate deduction that you are trying to make. You didn't know, Lawrence, what I was doing with the rest of my life. You didn't know what my family situation may have been. Maybe, just maybe, I had a sick relative, which is why I might not have been sitting in, or doing the Freedom Rides. So what I'm saying, Lawrence, is, with all due respect my friend, your deduction is incorrect, and it's not logical, okay?”

Herman Cain (1945) American writer, businessman and activist

referring to "This is Herman Cain!" recounting that Herman read about sit-ins and Freedom Rides, and followed his father's advice to "stay out of trouble".

Life , Books , Family , Question

“The theory of perspective was taught in painting schools from the sixteenth century onward according to principles laid down by the masters… However, their treatises on perspective had on the whole been precept, rule, and ad hoc procedure; they lacked a solid mathematical basis. In the period from 1500 to 1600 artists and subsequently mathematicians put the subject on a satisfactory deductive basis, and it passed from quasi-empirical art to a true science. Definitive works on perspective were written much later by eighteenth-century mathematicians Brook Taylor and J. H. Lambert.”

Morris Kline (1908–1992) American mathematician

Source: Mathematical Thought from Ancient to Modern Times (1972), p. 183

School , Art , Mathematics , Science

“At any rate, it would detract sadly from the richness of the game if deduction of character from a player's style was a forbidden pursuit, for undoubtedly the main reason why cricketers are remembered for years, for decades, after the heroes of other sports are forgotten is that they set the impress of character, apart from technical batting or bowling, on the minds of those who watched them, and whether that cricket-character falsely represented the real man is, in the last analysis, unimportant.”

Dudley Carew (1903–1981) English journalist, writer, poet and film critic

To the Wicket (1946)

Game , Sport , Falseness

“You can’t remember sex. You can remember the fact of it, and recall the setting, and even the details, but the sex of the sex cannot be remembered, the substantive truth of it, it is by nature self-erasing, you can remember its anatomy and be left with a judgment as to the degree of your liking of it, but whatever it is as a splurge of being, as a loss, as a charge of the conviction of love stopping your heart like your execution, there is no memory of it in the brain, only the deduction that it happened and that time passed, leaving you with a silhouette that you want to fill in again.”

E.L. Doctorow book Billy Bathgate

Billy Bathgate (1989), Ch. 16

Love , Truth , Sex , Nature

“It is estimated that the value of the crops for this harvest year may reach $13,000,000,000, which is an increase of over $3,000,000,000 in three years. It compares with $7,100,000,000 in 1913, arid if we make deduction from the figures of 1924 for the comparatively decreased value of the dollar, the yield this year still exceeds 1913 in purchasing power by over $1,000,000,000, and in this interval there has been no increase in the number of farmers. Mostly by his own effort the farmer has decreased the cost of production. A marked increase in the price of his products and some decrease in the price of his supplies has brought him about to a parity with the rest of the Nation. The crop area of this season is estimated at 370,000,000 acres, which is a decline of 3,000,000 acres from last year, and 6,000,000 acres from 1919. This has been a normal and natural application of economic laws, which has placed agriculture on a foundation which is undeniably sound and beginning to be satisfactory.”

Calvin Coolidge (1872–1933) American politician, 30th president of the United States (in office from 1923 to 1929)

1920s, Second State of the Union Address (1924)

Law , Nature , Effort , Season

“There is a paradigm shift towards a distributed and integrated enterprise. Currently, computer systems that support enterprise functions were created independently. This hampers enterprise integration Therefore, there is a need for a computer based data model which provides a shared and well deﬁned terminology of an enterprise, and has the capability to deductively answer common sense questions.
This paper discusses how TOVE tackles these needs by deﬁning a framework for modeling generic level representations such as activities, time, and resources. Since there has never been a well-deﬁned set of criteria to evaluate such models, this paper also introduces a set of evaluation criteria which may be used to evaluate modelling efforts.”

Mark S. Fox (1952) Canadian computer scientist and Professor of Industrial Engineering

Mark S. Fox, John F. Chionglo, and Fadi G. Fadel (1993) " A common-sense model of the enterprise http://windsor.mie.utoronto.ca/enterprise-modelling/papers/fox-ierc93.pdf." Proceedings of the 2nd Industrial Engineering Research Conference. Vol. 1. 1993.

Question , Support , Sense , Effort

“Thematic analysis is a process for encoding quantitative information. The encoding requires an explicit "code". This may be a list of themes; a complex model with themes, indicators, and qualifications that are causally related; or something in between these two forms. A theme is a pattern found in the information that at minimum describes and organizes the possible observations and at maximum interprets aspects of the phenomenon. A theme may be identified at the manifest level (directly observable in the information) or at the latent level (underlying the phenomenon). The themes may be initially generated inductively from the raw information or generated deductively from theory or prior research.”

Richard Boyatzis (1946) American business theorist

Source: Transforming qualitative information (1998), p. vi-vii.

“So in order to understand the physics one must always have a neat balance and contain in his head all of the various propositions and their interelationships because the laws often extend beyond the range of their deductions. This will only have no importance when all the laws are known.”

Richard Feynman book The Character of Physical Law

Source: The Character of Physical Law (1965), chapter 2, “ The Relation of Mathematics to Physics http://www.youtube.com/watch?v=M9ZYEb0Vf8U”

Law , Understanding

“How much do you think it costs to go to college? Most people are likely to answer by adding together their expenditures on tuition, room and board, books, and the like, and then deducting any scholarship funds they may receive. Suppose that amount comes to $15,000.
Economists keep score differently. They first want to know how much you would be earning if you were not attending college. Suppose that salary is $20,000 per year. This may seem irrelevant, but because you give up these earnings by attending college, they must be added to your tuition bill. You have that much less income because of your education. On the other side of the ledger, economists would not count all of the university’s bill for room and board as part of the costs of your education. They would want to know how much more it costs you to live at school rather than at home. Economists would count only these extra costs as an educational expense because you would have incurred these costs whether or not you attend college. On balance, college is probably costing you much more than you think. And, as we will see later, taking opportunity cost into account in any personal planning will help you to make more rational decisions.”

Alan Blinder (1945) economist

William Baumol and Alan Blinder, Economics: Principles and Policy (2011), Ch. 1 : What is Economics?

People , Books , Education , School

“[a new order].. independent of the values of the feelings, and the description and imitation of nature... The value of technique beauty without artistic intention resides in its organism and can be deducted at the same time by its geometric ambitions. I can therefore speak of a new order: the architecture of the technical world. Since the industrial object belongs to the architectonic order, it is assigned an important role in today's artistic creation.”

Fernand Léger (1881–1955) French painter

Quote from Leger's lecture "The aesthetics of the machine", in Paris, June 1924; as quoted by Paul Westheim in Confessions of Artists. - Letters, Memoirs and Observations of Contemporary Artists; Propyläen Publishing House, Berlin, 1925, p. 324; cited in Review by Francesco Mazzaferro http://letteraturaartistica.blogspot.nl/2016/03/paul-westheim1717.html
Quotes of Fernand Leger, 1920's

World , Beauty , Feeling , Nature

“[T]he human reason discovers new relations between things not by deduction, but by that unpredictable blend of speculation and insight… induction, which—like other forms of imagination—cannot be formalized.”

Jacob Bronowski (1908–1974) Polish-born British mathematician

"The Reach of Imagination" (1967)

Imagination

“There’s nothing like deduction. We’ve determined everything about our problem but the solution.”

Isaac Asimov book I, Robot

“Runaround”, p. 41; see above for the Three Laws of Robotics, also drawn from this story
I, Robot (1950)

Problem

“Oh, and some nasty stuff in there! It looked to be a bite, almost. Holyfield is very unhappy, look at this! It looked as if Tyson bared his teeth at one stage in the exchange. He bit his ear! Well, feelings are running very, very hot indeed in there. Holyfield was outraged by that. Now what is the referee going to do about that? One point deduction for Tyson! One point deducted from Mike Tyson, for biting Holyfield's ear. Now, let's take a look again. Well, this is getting like a street fight.”

Ian Darke (1950) British association football and boxing commentator

Evander Holyfield vs. Mike Tyson II https://listenonrepeat.com/watch/?v=xlIOqypvT-g#Mike_Tyson_Bites_Holyfields_Ear_Clean_Off (28 June 1997).
1990s, 1997, Evander Holyfield vs. Mike Tyson II (June 1997)

Feeling , Fight

“Beating the market is a zero-sum game for investors. Money managers, as a group, must provide the market return… But that return comes only before their exorbitant fees, operating expenses, and portfolio turnover costs are deducted. The zero-sum game before costs becomes a loser’s game after costs.”

John Bogle (1929–2019)

Gilbert Lecture, Princeton University, Feb 21, 2013

Money , Game

“I hope I may claim in the present work to have made it probable that the laws of arithmetic are analytic judgments and consequently a priori. Arithmetic thus becomes simply a development of logic, and every proposition of arithmetic a law of logic, albeit a derivative one. To apply arithmetic in the physical sciences is to bring logic to bear on observed facts; calculation becomes deduction.”

Gottlob Frege book The Foundations of Arithmetic

Gottlob Frege (1950 [1884]). The Foundations of Arithmetic. p. 99.

Law , Hope , Science

“Truly, though kingship be not a title but a name of office that runs through the law, yet it is not so ratione nominis, but from what is signified. It is a name of office, plainly implying a Supreme Authority. Is it more, or can it be stretched to more? I say, it is a name of office, plainly implying the Supreme Authority, and if it be so, why then I would suppose, (I am not peremptory in any thing that is matter of deduction or inference of my own,) why then I should suppose that whatsoever name hath been or shall be the name, in which the Supreme Authority shall act; why, (I say) if it had been those four or five letters, or whatsoever else it had been, that signification goes to the thing. Certainly it does, and not to the name. Why then, there can be no more said, but this, why this hath been fixt, so it may have been unfixt.”

Oliver Cromwell (1599–1658) English military and political leader

Answer to the Conference at the Committee at Whitehall, Second Protectorate Parliament http://www.british-history.ac.uk/report.asp?compid=36885 (13 April 1657), quoted in The Diary of Thomas Burton, esq., volume 2: April 1657 - February 1658 (1828), pp. 496-497

Law

“Everyone who wishes to help bring the world out of the economic woes will line up to get a chip implanted! It's safe, simple and already available. It's been tested on animals for years. One little chip under the skin and everyone can be identified and conduct business electronically! No more theft, bad checks, waiting for checks to clear, stolen credit cards, armored cars, stolen ID, waiting lines at stores or airports, etc. Just little archways to walk through that can quickly scan who you are and automatically deduct the “cash” from your account or verify your identity! Simple! Anyone who resists this “obvious solution” will be an enemy of the state. Oh, and one more minor insignificant thing. No more privacy or independence. Big brother will be watching everything.”

Kent Hovind (1953) American young Earth creationist

Source: What On Earth Is About To Happen… For Heaven’s Sake? (2013), p. 140

World , Cars , Business , Waiting

“As to my freedom, which you say I can have, there is nothing to be gained on that score, as I got my free papers in 1864 from the Provost-Marshal-General of the Department of Nashville. Mandy says she would be afraid to go back without some proof that you were disposed to treat us justly and kindly; and we have concluded to test your sincerity by asking you to send us our wages for the time we served you. This will make us forget and forgive old scores, and rely on your justice and friendship in the future. I served you faithfully for thirty-two years, and Mandy twenty years. At twenty-five dollars a month for me, and two dollars a week for Mandy, our earnings would amount to eleven thousand six hundred and eighty dollars. Add to this the interest for the time our wages have been kept back, and deduct what you paid for our clothing, and three doctor's visits to me, and pulling a tooth for Mandy, and the balance will show what we are in justice entitled to. Please send the money by Adams's Express, in care of V. Winters, Esq., Dayton, Ohio. If you fail to pay us for faithful labors in the past, we can have little faith in your promises in the future.”

Jordan Anderson (1825–1907) Freed slave

"Letter from a Freedman to His Old Master"

Money , Friendship , Faith , Justice