| If, however, I regard all things not as phenomena, but as things in themselves and objects of understanding alone, they, although substances, may be considered as dependent, in respect of their existence, on a foreign cause. |
| But this would require a very different meaning in the words, a meaning which could not apply to phenomena as objects of possible experience. |
| How a thing can be changed, how it is possible that upon one state existing in one point of time, an opposite state should follow in another point of time--of this we have not the smallest conception a priorI. There is requisite for this the knowledge of real powers, which can only be given empirically; for example, knowledge of moving forces, or, in other words, of certain successive phenomena (as movements) which indicate the presence of such forces. |
| But the form of every change, the condition under which alone it can take place as the coming into existence of another state (be the content of the change, that is, the state which is changed, what it may), and consequently the succession of the states themselves can very well be considered a priori, in relation to the law of causality and the conditions of time.* |
| [*Footnote; It must be remarked that I do not speak of the change of certain relations, but of the change of the state. |
| Thus, when a body moves in a uniform manner, it does not change its state (of motion); but only when all motion increases or decreases.] |
| When a substance passes from one state, a, into another state, b, the point of time in which the latter exists is different from, and subsequent to that in which the former existed. |
| In like manner, the second state, as reality (in the phenomenon), differs from the first, in which the reality of the second did not exist, as b from zero. |
| That is to say, if the state, b, differs from the state, a, only in respect to quantity, the change is a coming into existence of b - a, which in the former state did not exist, and in relation to which that state is = O. |
| Now the question arises how a thing passes from one state = a, into another state = b. |
| Between two moments there is always a certain time, and between two states existing in these moments there is always a difference having a certain quantity (for all parts of phenomena are in their turn quantities). |
| Consequently, every transition from one state into another is always effected in a time contained between two moments, of which the first determines the state which leaves, and the second determines the state into the thing passes. |
| the thing leaves, and the second determines the state into which the thing Both moments, then, are limitations of the time of a change, consequently of the intermediate state between both, and as such they belong to the total of the change. |
| Now every change has a cause, which evidences its causality in the whole time during which the charge takes place. |
| The cause, therefore, does not produce the change all at once or in one moment, but in a time, so that, as the time gradually increases from the commencing instant, a, to its completion at b, in like manner also, the quantity of the reality (b - a) is generated through the lesser degrees which are contained between the first and last. |
| All change is therefore possible only through a continuous action of the causality, which, in so far as it is uniform, we call a momentum. |
| The change does not consist of these momenta, but is generated or produced by them as their effect. |
| Such is the law of the continuity of all change, the ground of which is that neither time itself nor any phenomenon in time consists of parts which are the smallest possible, but that, notwithstanding, the state of a thing passes in the process of a change through all these parts, as elements, to its second state. |
| There is no smallest degree of reality in a phenomenon, just as there is no smallest degree in the quantity of time; and so the new state of reality grows up out of the former state, through all the infinite degrees thereof, the differences of which one from another, taken all together, are less than the difference between o and a. |
| It is not our business to inquire here into the utility of this principle in the investigation of nature. |
| But how such a proposition, which appears so greatly to extend our knowledge of nature, is possible completely a priori, is indeed a question which deserves investigation, although the first view seems to demonstrate the truth and reality of the principle, and the question, how it is possible, may be considered superfluous. |