Immanuel Kant - Kant's Three Critiques

Table of Contents

1. Time is not an empirical conception. For neither coexistence nor succession would be perceived by us, if the representation of time did not exist as a foundation a priori . Without this presupposition we could not represent to ourselves that things exist together at one and the same time, or at different times, that is, contemporaneously, or in succession.

2. Time is a necessary representation, lying at the foundation of all our intuitions. With regard to phenomena in general, we cannot think away time from them, and represent them to ourselves as out of and unconnected with time, but we can quite well represent to ourselves time void of phenomena. Time is therefore given a priori . In it alone is all reality of phenomena possible. These may all be annihilated in thought, but time itself, as the universal condition of their possibility, cannot be so annulled.

3. On this necessity a priori is also founded the possibility of apodeictic principles of the relations of time, or axioms of time in general, such as: “Time has only one dimension,” “Different times are not coexistent but successive” (as different spaces are not successive but coexistent). These principles cannot be derived from experience, for it would give neither strict universality, nor apodeictic certainty. We should only be able to say, “so common experience teaches us,” but not “it must be so.” They are valid as rules, through which, in general, experience is possible; and they instruct us respecting experience, and not by means of it.

4. Time is not a discursive, or as it is called, general conception, but a pure form of the sensuous intuition. Different times are merely parts of one and the same time. But the representation which can only be given by a single object is an intuition. Besides, the proposition that different times cannot be coexistent could not be derived from a general conception. For this proposition is synthetical, and therefore cannot spring out of conceptions alone. It is therefore contained immediately in the intuition and representation of time.

5. The infinity of time signifies nothing more than that every determined quantity of time is possible only through limitations of one time lying at the foundation. Consequently, the original representation, time, must be given as unlimited. But as the determinate representation of the parts of time and of every quantity of an object can only be obtained by limitation, the complete representation of time must not be furnished by means of conceptions, for these contain only partial representations. Conceptions, on the contrary, must have immediate intuition for their basis.

I may here refer to what is said above (§§ 5, 3), where, for the sake of brevity, I have placed under the head of metaphysical exposition, that which is properly transcendental. Here I shall add that the conception of change, and with it the conception of motion, as change of place, is possible only through and in the representation of time; that if this representation were not an intuition (internal) a priori , no conception, of whatever kind, could render comprehensible the possibility of change, in other words, of a conjunction of contradictorily opposed predicates in one and the same object, for example, the presence of a thing in a place and the non-presence of the same thing in the same place. It is only in time that it is possible to meet with two contradictorily opposed determinations in one thing, that is, after each other. Thus our conception of time explains the possibility of so much synthetical knowledge a priori , as is exhibited in the general doctrine of motion, which is not a little fruitful.

(a) Time is not something which subsists of itself, or which inheres in things as an objective determination, and therefore remains, when abstraction is made of the subjective conditions of the intuition of things. For in the former case, it would be something real, yet without presenting to any power of perception any real object. In the latter case, as an order or determination inherent in things themselves, it could not be antecedent to things, as their condition, nor discerned or intuited by means of synthetical propositions a priori . But all this is quite possible when we regard time as merely the subjective condition under which all our intuitions take place. For in that case, this form of the inward intuition can be represented prior to the objects, and consequently a priori .

(b) Time is nothing else than the form of the internal sense, that is, of the intuitions of self and of our internal state. For time cannot be any determination of outward phenomena. It has to do neither with shape nor position; on the contrary, it determines the relation of representations in our internal state. And precisely because this internal intuition presents to us no shape or form, we endeavour to supply this want by analogies, and represent the course of time by a line progressing to infinity, the content of which constitutes a series which is only of one dimension; and we conclude from the properties of this line as to all the properties of time, with this single exception, that the parts of the line are coexistent, whilst those of time are successive. From this it is clear also that the representation of time is itself an intuition, because all its relations can be expressed in an external intuition.

(c) Time is the formal condition a priori of all phenomena whatsoever. Space, as the pure form of external intuition, is limited as a condition a priori to external phenomena alone. On the other hand, because all representations, whether they have or have not external things for their objects, still in themselves, as determinations of the mind, belong to our internal state; and because this internal state is subject to the formal condition of the internal intuition, that is, to time — time is a condition a priori of all phenomena whatsoever — the immediate condition of all internal, and thereby the mediate condition of all external phenomena. If I can say a priori , “All outward phenomena are in space, and determined a priori according to the relations of space,” I can also, from the principle of the internal sense, affirm universally, “All phenomena in general, that is, all objects of the senses, are in time and stand necessarily in relations of time.”

If we abstract our internal intuition of ourselves and all external intuitions, possible only by virtue of this internal intuition and presented to us by our faculty of representation, and consequently take objects as they are in themselves, then time is nothing. It is only of objective validity in regard to phenomena, because these are things which we regard as objects of our senses. It no longer objective if we make abstraction of the sensuousness of our intuition, in other words, of that mode of representation which is peculiar to us, and speak of things in general. Time is therefore merely a subjective condition of our (human) intuition (which is always sensuous, that is, so far as we are affected by objects), and in itself, independently of the mind or subject, is nothing. Nevertheless, in respect of all phenomena, consequently of all things which come within the sphere of our experience, it is necessarily objective. We cannot say, “All things are in time,” because in this conception of things in general, we abstract and make no mention of any sort of intuition of things. But this is the proper condition under which time belongs to our representation of objects. If we add the condition to the conception, and say, “All things, as phenomena, that is, objects of sensuous intuition, are in time,” then the proposition has its sound objective validity and universality a priori .