George Boole: Principle

“It is upon the foundation of this general principle, that I purpose to establish the Calculus of Logic, and that I claim for it a place among the acknowledged forms of Mathematical Analysis,”

George Boole

Source: 1840s, The Mathematical Analysis of Logic, 1847, p. iii
Context: That to the existing forms of Analysis a quantitative interpretation is assigned, is the result of the circumstances by which those forms were determined, and is not to be construed into a universal condition of Analysis. It is upon the foundation of this general principle, that I purpose to establish the Calculus of Logic, and that I claim for it a place among the acknowledged forms of Mathematical Analysis, regardless that in its object and in its instruments it must at present stand alone.

Mathematics

“A studious person may neglect his business for the sake of books; but if he does this, it is not his books that are to blame, but his want of principle of of firmness.”

George Boole

Attributed to George Boole : Des MacHale (1985) George Boole: his life and work. p. 5
Attributed from posthumous publications

Books , Business , Personality

“THEY who are acquainted with the present state of the theory of Symbolical Algebra, are aware, that the validity of the processes of analysis does not depend upon the interpretation of the symbols which are employed, but solely upon the laws of their combination. Every system of interpretation which does not affect the truth of the relations supposed, is equally admissible, and it is thus that the same process may, under one scheme of interpretation, represent the solution of a question on the properties of numbers, under another, that of a geometrical problem, and under a third, that of a problem of dynamics or optics. This principle is indeed of fundamental importance; and it may with safety be affirmed, that the recent advances of pure analysis have been much assisted by the influence which it has exerted in directing the current of investigation.”

George Boole

Source: 1840s, The Mathematical Analysis of Logic, 1847, p. ii: Lead paragraph of the Introduction

Truth , Law , Question , Problem

“The principles of the theory of probabilities [cannot] serve to guide us in the election of… [scientific] hypotheses.”

George Boole

Source: 1850s, An Investigation of the Laws of Thought (1854), p. 375, as cited in: Lev D. Beklemishev (2000) Provability, Computability and Reflection, p. 432

“It is not possible, I think, to rise from the perusal of the arguments of Clark and Spinoza without a deep conviction of the futility of all endeavors to establish, entirely à priori, the existence of an Infinite Being, His attributes, and His relation to the universe. The fundamental principle of all such speculations, viz. that whatever we can clearly conceive, must exist, fails to accomplish its end, even when its truth is admitted. For how shall the finite comprehend the infinite? Yet must the possibility of such conception be granted, and in something more than the sense of a mere withdrawal of the limits of phænomal existence, before any solid ground can be established for the knowledge, à priori, of things infinite and eternal.”

George Boole

George Boole, An Investigation of the Laws of Thought (1854) Ch. 13. Clarke and Spinoza, pp. 216-217. https://books.google.com/books?id=DqwAAAAAcAAJ&pg=PA216
A - F

Truth , Knowledge , Thinking , Sense

“Let us conceive, then, of an algebra in which the symbols x, y z etc. admit indifferently of the values 0 and 1, and of these values alone The laws, the axioms, and the processes, of such an Algebra will be identical in their whole extend with the laws, the axioms, and the processes of an Algebra of Logic. Difference of interpretation will alone divide them. Upon this principle the method of the following work is established.”

George Boole

Source: 1850s, An Investigation of the Laws of Thought (1854), p. 37; Cited in: William Torrey Harris (1879) The Journal of Speculative Philosophy, p. 109

Law , Indifference

“That axiom of Metaphysicians which is termed the principle of contradiction and which affirms that it is impossible for anything to possess a quality, and in the same time not to possess it, is a consequence of the fundamental law of thought, whose expression is x²=x.”

George Boole

Source: 1850s, An Investigation of the Laws of Thought (1854), p. 49: as cited in: " Professor Boole's Mathematical theory http://books.google.com/books?id=tBNLAAAAYAAJ&pg=PA62" in: Henry Longueville Manse, Philosophical pamphlets, (1853), p. 6

Law , Time

“It has been said, that the principle involved in the above and in similar applications is that of the equal distribution of our knowledge, or rather of our ignorance the assigning to different states of things of which we know nothing, and upon the very ground that we know nothing, equal degrees of probability. I apprehend, however, that this is an arbitrary method of procedure. Instances may occur, and one such has been adduced, in which different hypotheses lead to the same final conclusion.”

George Boole

Source: 1850s, An Investigation of the Laws of Thought (1854), p. 370

Knowledge

“The following work is not a republication of a former treatise by the Author, entitled, "The Mathematical Analysis of Logic." Its earlier portion is indeed devoted to the same object, and it begins by establishing the same system of fundamental laws, but its methods are more general, and its range of applications far wider. It exhibits the results, matured by some years of study and reflection, of a principle of investigation relating to the intellectual operations, the previous exposition of which was written within a few weeks after its idea had been conceived.”

George Boole

Source: 1850s, An Investigation of the Laws of Thought (1854), p. i; Preface, lead paragraph

Law , Mathematics , Idea , Study