“_The idea of time does not originate in, but is presupposed by the senses._ When a number of things act upon the senses, it is only by means of the idea of time that they can be represented whether as simultaneous or as successive. Nor does succession generate the conception of time; but stimulates us to form it. Thus the notion of time, even if acquired through experience, is very badly defined as being a series of actual things existing one _after_ another. For I can understand what the word _after_ signifies only if I already know what time means. For those things are _after_ one another which exist at _different_ times, as those are _simultaneous_ which exist at one and the same time.”[492] =Second Argument.=--Kant again applies to time the argument already employed by him in dealing with space. The thesis is that time is given _a priori_. Proof is found in the fact that it cannot be thought away, _i.e._ in the fact of its subjective necessity. From this subjective necessity follows its objective necessity, so far as all appearances are concerned. In the second edition Kant added a phrase--“as the general condition of their possibility”--which is seriously misleading. The concluding sentence is thereby made to read as if Kant were arguing from the objective necessity of time, _i.e._ from its necessity as a constituent in the appearances apprehended, to its apriority. It is indeed possible that Kant himself regarded this objective necessity of time as contributing to the proof of its apriority. But no such argument can be accepted. Time may be necessary to appearances, _once appearances are granted_. This does not, however, prove that it must therefore precede them _a priori_. This alteration in the second edition is an excellent, though unfortunate, example of Kant’s invincible carelessness in the exposition of his thought. It has contributed to a misreading by Herbart and others of this and of the corresponding argument on space. “Let us not talk of an absolute space as the presupposition of all our constructed figures. Possibility is nothing but thought, and it arises only when it is thought. Space is nothing but possibility, for it contains nothing save images of the existent; and absolute space is nothing save the abstracted general possibility of such constructions, abstracted from it after completion of the construction. The necessity of the representation of space ought never to have played any rôle in philosophy. To think away space is to think away the _possibility_ of that which has been previously posited as _actual_. Obviously that is impossible, and the opposite is necessary.”[493]