| The time between the causality of the cause and its immediate effect may entirely vanish, and the cause and effect be thus simultaneous, but the relation of the one to the other remains always determinable according to time. |
| If, for example, I consider a leaden ball, which lies upon a cushion and makes a hollow in it, as a cause, then it is simultaneous with the effect. |
| But I distinguish the two through the relation of time of the dynamical connection of both. |
| For if I lay the ball upon the cushion, then the hollow follows upon the before smooth surface; but supposing the cushion has, from some cause or another, a hollow, there does not thereupon follow a leaden ball. |
| Thus, the law of succession of time is in all instances the only empirical criterion of effect in relation to the causality of the antecedent cause. |
| The glass is the cause of the rising of the water above its horizontal surface, although the two phenomena are contemporaneous. |
| For, as soon as I draw some water with the glass from a larger vessel, an effect follows thereupon, namely, the change of the horizontal state which the water had in the large vessel into a concave, which it assumes in the glass. |
| This conception of causality leads us to the conception of action; that of action, to the conception of force; and through it, to the conception of substance. |
| As I do not wish this critical essay, the sole purpose of which is to treat of the sources of our synthetical cognition a priori, to be crowded with analyses which merely explain, but do not enlarge the sphere of our conceptions, I reserve the detailed explanation of the above conceptions for a future system of pure reason. |
| Such an analysis, indeed, executed with great particularity, may already be found in well-known works on this subject. |
| But I cannot at present refrain from making a few remarks on the empirical criterion of a substance, in so far as it seems to be more evident and more easily recognized through the conception of action than through that of the permanence of a phenomenon. |
| Where action (consequently activity and force) exists, substance also must exist, and in it alone must be sought the seat of that fruitful source of phenomena. |
| Very well. |
| But if we are called upon to explain what we mean by substance, and wish to avoid the vice of reasoning in a circle, the answer is by no means so easy. |
| How shall we conclude immediately from the action to the permanence of that which acts, this being nevertheless an essential and peculiar criterion of substance (phenomenon)? |
| But after what has been said above, the solution of this question becomes easy enough, although by the common mode of procedure--merely analysing our conceptions--it would be quite impossible. |
| The conception of action indicates the relation of the subject of causality to the effect. |
| Now because all effect consists in that which happens, therefore in the changeable, the last subject thereof is the permanent, as the substratum of all that changes, that is, substance. |
| For according to the principle of causality, actions are always the first ground of all change in phenomena and, consequently, cannot be a property of a subject which itself changes, because if this were the case, other actions and another subject would be necessary to determine this change. |
| From all this it results that action alone, as an empirical criterion, is a sufficient proof of the presence of substantiality, without any necessity on my part of endeavouring to discover the permanence of substance by a comparison. |
| Besides, by this mode of induction we could not attain to the completeness which the magnitude and strict universality of the conception requires. |