Quotes from book
Critique of Pure Reason

Name: Critique of Pure Reason
Author: Immanuel Kant

Immanuel KantOriginal title Critik der reinen Vernunft (German, 1781)

The Critique of Pure Reason is a book by the German philosopher Immanuel Kant, in which the author seeks to determine the limits and scope of metaphysics. Also referred to as Kant's "First Critique", it was followed by the Critique of Practical Reason and the Critique of Judgment . In the preface to the first edition, Kant explains that by a "critique of pure reason" he means a critique "of the faculty of reason in general, in respect of all knowledge after which it may strive independently of all experience" and that he aims to reach a decision about "the possibility or impossibility of metaphysics".

“Man must be disciplined, for he is by nature raw and wild..”

Immanuel Kant book Critique of Pure Reason

Source: Critique of Pure Reason

“All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.”

Immanuel Kant book Critique of Pure Reason

B 730; Variant translation: All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.
Variant: All human knowledge begins with intuitions, proceeds from thence to concepts, and ends with ideas.
Source: Critique of Pure Reason (1781; 1787)

“Thoughts without content are empty, intuitions without concepts are blind.”

Immanuel Kant book Critique of Pure Reason

A 51, B 75
Source: Critique of Pure Reason (1781; 1787)
Context: Thoughts without content are empty, intuitions without concepts are blind. The understanding can intuit nothing, the senses can think nothing. Only through their unison can knowledge arise.

“Whereas the beautiful is limited, the sublime is limitless, so that the mind in the presence of the sublime, attempting to imagine what it cannot, has pain in the failure but pleasure in contemplating the immensity of the attempt”

Immanuel Kant book Critique of Pure Reason

Source: Critique of Pure Reason

“But though all our knowledge begins with experience, it by no means follows, that all arises out of experience.”

Immanuel Kant book Critique of Pure Reason

Introduction I. Of the Difference Between Pure and Empirical Knowledge
Critique of Pure Reason (1781; 1787)
Variant: That all our knowledge begins with experience there can be no doubt.
Context: That all our knowledge begins with experience there can be no doubt. For how is it possible that the faculty of cognition should be awakened into exercise otherwise than by means of objects which affect our senses, and partly of them selves produce representations, partly rouse our powers of understanding into activity, to compare, to connect, or to separate these, and so to convert the raw material of our sensuous impressions into a knowledge of objects, which is called experience? In respect of time, therefore, no knowledge of ours is antecedent to experience, but begins with it. But though all our knowledge begins with experience, it by no means follows, that all arises out of experience. For, on the contrary, it is quite possible that our empirical knowledge is a compound of that which we receive through impressions, and that which the faculty of cognition supplies from itself (sensuous impressions giving merely the occasion)... It is, therefore, a question which requires close investigation, and is not to be answered at first sight,—whether there exists a knowledge altogether independent of experience, and even of all sensuous impressions? Knowledge of this kind is called à priori, in contradistinction to empirical knowledge which has its sources à posteriori, that is, in experience.

“It is therefore correct to say that the senses do not err — not because they always judge rightly, but because they do not judge at all.”

Immanuel Kant book Critique of Pure Reason

A 293, B 350
Critique of Pure Reason (1781; 1787)

“The light dove, cleaving the air in her free flight, and feeling its resistance, might imagine that its flight would be still easier in empty space.”

Immanuel Kant book Critique of Pure Reason

B 8
Critique of Pure Reason (1781; 1787)

“All our knowledge falls with the bounds of experience.”

Immanuel Kant book Critique of Pure Reason

A 146, B 185
Critique of Pure Reason (1781; 1787)

“Human reason is by nature architectonic.”

Immanuel Kant book Critique of Pure Reason

B 502
Critique of Pure Reason (1781; 1787)

“For it is extremely absurd to expect to be enlightened by reason, and yet to prescribe to her beforehand on which side she must incline.”

Immanuel Kant book Critique of Pure Reason

A 747, B 775; as translated by F. Max Mueller
Critique of Pure Reason (1781; 1787)

“All thought must, directly or indirectly, by way of certain characters, relate ultimately to intuitions, and therefore, with us, to sensibility, because in no other way can an object be given to us.”

Immanuel Kant book Critique of Pure Reason

B 33
Critique of Pure Reason (1781; 1787)

“Philosophical knowledge is the knowledge gained by reason from concepts; mathematical knowledge is the knowledge gained by reason from the construction of concepts.”

Immanuel Kant book Critique of Pure Reason

A 713, B 741
Critique of Pure Reason (1781; 1787)

“Criticism alone can sever the root of materialism, fatalism, atheism, free-thinking, fanaticism, and superstition, which can be injurious universally; as well as of idealism and skepticism, which are dangerous chiefly to the Schools, and hardly allow of being handed on to the public.”

Immanuel Kant book Critique of Pure Reason

B xxxiv
Critique of Pure Reason (1781; 1787)

“Mathematics, from the earliest times to which the history of human reason can reach, has followed, among that wonderful people of the Greeks, the safe way of science. But it must not be supposed that it was as easy for mathematics as for logic, in which reason is concerned with itself alone, to find, or rather to make for itself that royal road. I believe, on the contrary, that there was a long period of tentative work (chiefly still among the Egyptians), and that the change is to be ascribed to a revolution, produced by the happy thought of a single man, whose experiments pointed unmistakably to the path that had to be followed, and opened and traced out for the most distant times the safe way of a science. The history of that intellectual revolution, which was far more important than the passage round the celebrated Cape of Good Hope, and the name of its fortunate author, have not been preserved to us. … A new light flashed on the first man who demonstrated the properties of the isosceles triangle (whether his name was Thales or any other name), for he found that he had not to investigate what he saw hi the figure, or the mere concepts of that figure, and thus to learn its properties; but that he had to produce (by construction) what he had himself, according to concepts a priori, placed into that figure and represented in it, so that, in order to know anything with certainty a priori, he must not attribute to that figure anything beyond what necessarily follows from what he has himself placed into it, in accordance with the concept.”

Immanuel Kant book Critique of Pure Reason

Preface to the Second Edition [Tr. F. Max Müller], (New York, 1900), p. 690; as cited in: Robert Edouard Moritz, Memorabilia mathematica or, The philomath's quotation-book https://openlibrary.org/books/OL14022383M/Memorabilia_mathematica, Published 1914. p. 10 <br class="br">Critique of Pure Reason (1781; 1787)

“Metaphysics has as the proper object of its enquiries three ideas only: God, freedom, and immortality.”

Immanuel Kant book Critique of Pure Reason

B 395
Critique of Pure Reason (1781; 1787)

“I have no knowledge of myself as I am, but merely as I appear to myself.”

Immanuel Kant book Critique of Pure Reason

B 158
Critique of Pure Reason (1781; 1787)

“Abbot Terrasson tells us that if the size of a book were measured not by the number of its pages but by the time required to understand it, then we could say about many books that they would be much shorter were they not so short.”

Immanuel Kant book Critique of Pure Reason

A xix
Critique of Pure Reason (1781; 1787)

“It is precisely in knowing its limits that philosophy consists.”

Immanuel Kant book Critique of Pure Reason

A 727, B 755
Critique of Pure Reason (1781; 1787)