Front Page Titles (by Subject) I: Of Logic in General - Critique of Pure Reason
The Online Library of Liberty
A project of Liberty Fund, Inc.
I: Of Logic in General - Friedrich Max Müller, Critique of Pure Reason 
Immanuel Kant’s Critique of Pure Reason. In Commemoration of the Centenary of its First Publication. Translated into English by F. Max Mueller (2nd revised ed.) (New York: Macmillan, 1922).
About Liberty Fund:
Liberty Fund, Inc. is a private, educational foundation established to encourage the study of the ideal of a society of free and responsible individuals.
The text is in the public domain.
Fair use statement:
This material is put online to further the educational goals of Liberty Fund, Inc. Unless otherwise stated in the Copyright Information section above, this material may be used freely for educational and academic purposes. It may not be used in any way for profit.
Of Logic in General
Our knowledge springs from two fundamental sources of our soul; the first receives representations (receptivity of impressions), the second is the power of knowing an object by these representations (spontaneity of concepts). By the first an object is given us, by the second the object is thought, in relation to that representation which is a mere determination of the soul. Intuition therefore and concepts constitute the elements of all our knowledge, so that neither concepts without an intuition corresponding to them, nor intuition without concepts can yield any real knowledge.
Both are either pure or empirical. They are empirical when sensation, presupposing the actual presence of the object, is contained in it. They are pure when no sensation is mixed up with the representation. The latter may be called the material of sensuous knowledge. Pure intuition therefore contains the form only by which [p. 51] something is seen, and pure conception the form only by which an object is thought. Pure intuitions and pure concepts only are possible a priori, empirical intuitions and empirical concepts a posteriori.
We call sensibility the receptivity of our soul, or its power of receiving representations whenever it is in any wise affected, while the understanding, on the contrary, is with us the power of producing representations, or the spontaneity of knowledge. We are so constituted that our intuition must always be sensuous, and consist of the mode in which we are affected by objects. What enables us to think the objects of our sensuous intuition is the understanding. Neither of these qualities or faculties is preferable to the other. Without sensibility objects would not be given to us, without understanding they would not be thought by us. Thoughts without contents are empty, intuitions without concepts are blind. Therefore it is equally necessary to make our concepts sensuous, i.e. to add to them their object in intuition, as to make our intuitions intelligible, [Editor: illegible word.] bring them under concepts. These two powers or faculties cannot exchange their functions. The understanding cannot see, the senses cannot think. By their union only can knowledge be produced. But this is no reason for confounding the share which belongs to each in the production of knowledge. On the contrary, they should always [p. 52] be carefully separated and distinguished, and we have therefore divided the science of the rules of sensibility in general, i.e. æsthetic, from the science of the rules of the understanding in general, i.e. logic.
Logic again can be taken in hand for two objects, either as logic of the general or of a particular use of the understanding. The former contains all necessary rules of thought without which the understanding cannot be used at all. It treats of the understanding without any regard to the different objects to which it may be directed. Logic of the particular use of the understanding contains rules how to think correctly on certain classes of objects. The former may be called Elementary Logic, the latter the Organum of this or that science. The latter is generally taught in the schools as a preparation for certain sciences, though, according to the real progress of the human understanding, it is the latest achievement, which does not become possible till the science itself is really made, and requires only a few touches for its correction and completion. For it is clear that the objects themselves must be very well known before it is possible to give rules according to which a science of them may be established.
General logic is either pure or applied. In the [p. 53] former no account is taken of any empirical conditions under which our understanding acts, i.e. of the influence of the senses, the play of imagination, the laws of memory, the force of habit, the inclinations, and therefore the sources of prejudice also, nor of anything which supplies or seems to supply particular kinds of knowledge; for all this applies to the understanding under certain circumstances of its application only, and requires experience as a condition of knowledge. General but pure logic has to deal with principles a priori only, and is a canon of the understanding and of reason, though with reference to its formal application only, irrespective of any contents, whether empirical or transcendental. General logic is called applied, if it refers to the rules of the use of our understanding under the subjective empirical conditions laid down in psychology. It therefore contains empirical principles, yet it is general, because referring to the use of the understanding, whatever its objects may be. It is neither a canon of the understanding in general nor an organum of any particular science, but simply a catharticon of the ordinary understanding.
In general logic, therefore, that part which is to constitute the science of pure reason must be entirely separated from that which forms applied, but for all [p. 54] that still general logic. The former alone is a real science, though short and dry, as a practical exposition of an elementary science of the understanding ought to be. In this logicians should never lose sight of two rules:—
1. As general logic it takes no account of the contents of the knowledge of the understanding nor of the difference of its objects. It treats of nothing but the mere form of thought.
2. As pure logic it has nothing to do with empirical principles, and borrows nothing from psychology (as some have imagined); psychology, therefore, has no influence whatever on the canon of the understanding. It proceeds by way of demonstration, and everything in it must be completely a priori.
What I call applied logic (contrary to common usage according to which it contains certain exercises on the rules of pure logic) is a representation of the understanding and of the rules according to which it is necessarily applied in concreto, i.e. under the accidental conditions of the subject, which may hinder or help its application, and are all given empirically only. It treats of attention, its impediments and their consequences, the sources of error, the states of doubt, hesitation, and conviction, etc., and general and pure logic stands to it in [p. 55] the same relation as pure ethics, which treat only of the necessary moral laws of a free will, to applied ethics, which consider these laws as under the influence of sentiments, inclinations, and passions to which all human beings are more or less subject. This can never constitute a true and demonstrated science, because, like applied logic, it depends on empirical and psychological principles.