Kant elaborates the idea of transcendental logic in the Second Part of “Transcendental Doctrine of The Elements” of the “Critique of Pure Reason”.
In this Part, there are four Sub Topic: Logic in General, Transcendental Logic, Division of General Logic into Analytic and Dialectic, and Division of Transcendental Logic into Transcendental Analytic and Dialectic.
Logic In General consists of two fundamental sources of knowledge:
sensibility i.e. the capacity to receive representations which consists of the Science of Aesthetic and How objects are given to us;
and understanding i.e. the power of knowing an object through representations which consists of The science of Logic and How an object is thought.
Kant claims that only through their union can knowledge arise.
According to Kant , there are two types of logic: logic in general contains absolutely necessary rules of thought viz. the logic of elements; and logic of the special employment of the understanding contains rules of correct thinking about certain kinds of objects viz. the logic of a particular science.
General logic consists of pure i.e. an abstracts from all empirical conditions, hence it deals with mere forms of thought; and consists of applied i.e. an understanding under subjective empirical conditions.
Kant characterizes transcendental logic not as an abstract from the entire content of knowledge.
It excludes only those modes of knowledge which have empirical content and treats the origin of modes in which we know objects.
Further, Kant claims that not every kinds of a priori knowledge should be called transcendental; only that by which we know that certain representations can be employed or are possible a priori.
Space is the knowledge that the representations are not empirical one.
Kant divides transcendental logic into transcendental analytic and dialectic.
He elaborates that transcendental analytic has two aspects: logic which deals with elements of pure knowledge yielded by understanding and logic in which no object can be thought.
In transcendental dialectic, a misuse of transcendental analytic and dialectic illusion may happen.
Dialectic is concerned with the fallacies produced when metaphysics is extended beyond possible experience; while the Analytic, about secure metaphysics, is divided into the Analytic of Concepts and the Analytic of Principles.
Kant distinguishes the science of the laws of sensibility i.e. aesthetic from the science of the laws of the understanding i.e. logic.
Logic in its turn may be considered as logic of the general or of the particular use of the understanding.
The first contains the absolutely necessary laws of thought without which no use what so ever of the understanding is possible.
It gives laws to the understanding without regard to the difference of objects on which it may be employed.
The second contains the laws of correct thinking upon a particular class of objects.
In a pure general logic we abstract all the empirical conditions under which the understanding is exercised.
It has to do merely with pure a priori principles.
It is a canon of understanding and reason but only in respect of the formal part of their use to be the content of what it may be empirical or transcendental.
According to Kant , in a pure general logic we must always bear in mind two rules.
First, as general logic, it makes abstraction of all content of the cognition of the understanding and of the difference of objects.
It has to do with nothing but the mere form of thought.
Second, as pure logic, it has no empirical principles and consequently draws nothing from psychology which therefore has no influence on the canon of the understanding.
It is a demonstrated doctrine in which everything in it must be certain completely a priori.
In an applied general logic we direct the laws of the use of the understanding under the subjective empirical conditions in which psychology teaches us.
It is an empirical principle although at the same time, it is in so far general, that it applies to the exercise of the understanding, without regard to the difference of objects.
Applied logic is a representation of the understanding and of the rules of its necessary employment in concreto under the accidental conditions of the subject which may either hinder or promote this employment in which they are all given only empirically.
Thus applied logic treats of attention, its impediments and consequences of the origin of error, of the state of doubt, hesitation, conviction, etc.
It relates pure general logic in the same way that pure morality.
It contains only the necessary moral laws of a free will, is related to practical ethics.
It considers these laws under all the impediments of feelings, inclinations, and passions to which peoples are more or less subjected.
It can never furnish us with a true and demonstrated science because it, as well as applied logic, requires empirical and psychological principles.
With regard to our cognition in respect of its mere form, it is equally manifest that logic exhibits the universal and necessary laws of the understanding and must in these very laws present us with criteria of truth.
Whatever contradicts these rules is false because the understanding is made to contradict its own universal laws of thought i.e. contradict to itself.
These criteria , however, apply solely to the form of truth, that is, of thought in general, and in so far they are perfectly accurate, yet not sufficient.
Although cognition may be perfectly accurate as to logical form or not self-contradictory, it is not withstanding quite possible that it may not stand in agreement with its object.
Consequently, the merely logical criterion of truth, namely, the accordance of cognition with the universal and formal laws of understanding and reason, is nothing more than the conditio sine qua non or negative condition of all truth.
In the expectation that there may be mathematical conceptions which relate a priori to objects, not as pure or sensuous intuitions, but merely as acts of pure thought, we form the idea of a science of pure understanding and rational cognition by cogitating objects entirely a priori.
This kind of science should determine the origin, the extent, and the objective validity of mathematical cognitions and must be called transcendental logic.
Like in general logic , the transcendental logic has to do with the laws of understanding and reason in relation to empirical as well as pure rational cognitions without distinction, but concerns itself with these only in an a priori relation to objects.
In transcendental logic we isolate the understanding and select from our cognition merely that part of thought which has its origin in the understanding alone.
Understanding and judgment accordingly possess in transcendental logic a canon of objectively valid, true exercise, and is comprehended in the analytical department of that logic.
However, reason, in her endeavors to arrive by a priori means at some true statement concerning objects and to extend cognition beyond the bounds of possible experience, is altogether dialectic.
Its illusory assertions cannot be constructed into a canon such as an analytic ought to contain.
Logical illusion , which consists merely in the imitation of the form of reason, arises entirely from a want of due attention to logical rules.
Transcendental dialectic will therefore content itself by exposing the illusory appearance in transcendental judgments and guarding us against it; but to make it, as in the case of logical illusion, entirely disappear and cease to be illusion is utterly beyond its power.
There is a merely formal logical use, in which it makes abstraction of all content of cognition; but there is also a real use, in as much as it contains in itself the source of certain conceptions and principles, which it does not borrow either from the senses or from the understanding.
As a division of reason into a logical and a transcendental faculty presents itself here, it becomes necessary to seek for a higher conception of this source of cognition which shall comprehend both conceptions.
Here we may expect, according to the analogy of the conceptions of the understanding, that the logical conception will give us the key to the transcendental, and that the table of the functions of the former will present us with the clue to the conceptions of mathematical reason.
Kant, I., 1787, “The Critique of Pure Reason: Preface To The Second Edition”, Translated By J. M. D. Meiklejohn, Retrieved 2003