| In other words, whatever follows or happens, must follow in conformity with a universal rule upon that which was contained in the foregoing state. |
| Hence arises a series of phenomena, which, by means of the understanding, produces and renders necessary exactly the same order and continuous connection in the series of our possible perceptions, as is found a priori in the form of internal intuition (time), in which all our perceptions must have place. |
| That something happens, then, is a perception which belongs to a possible experience, which becomes real only because I look upon the phenomenon as determined in regard to its place in time, consequently as an object, which can always be found by means of a rule in the connected series of my perceptions. |
| But this rule of the determination of a thing according to succession in time is as follows; "In what precedes may be found the condition, under which an event always (that is, necessarily) follows." From all this it is obvious that the principle of cause and effect is the principle of possible experience, that is, of objective cognition of phenomena, in regard to their relations in the succession of time. |
| The proof of this fundamental proposition rests entirely on the following momenta of argument. |
| To all empirical cognition belongs the synthesis of the manifold by the imagination, a synthesis which is always successive, that is, in which the representations therein always follow one another. |
| But the order of succession in imagination is not determined, and the series of successive representations may be taken retrogressively as well as progressively. |
| But if this synthesis is a synthesis of apprehension (of the manifold of a given phenomenon), then the order is determined in the object, or to speak more accurately, there is therein an order of successive synthesis which determines an object, and according to which something necessarily precedes, and when this is posited, something else necessarily follows. |
| If, then, my perception is to contain the cognition of an event, that is, of something which really happens, it must be an empirical judgement, wherein we think that the succession is determined; that is, it presupposes another phenomenon, upon which this event follows necessarily, or in conformity with a rule. |
| If, on the contrary, when I posited the antecedent, the event did not necessarily follow, I should be obliged to consider it merely as a subjective play of my imagination, and if in this I represented to myself anything as objective, I must look upon it as a mere dream. |
| Thus, the relation of phenomena (as possible perceptions), according to which that which happens is, as to its existence, necessarily determined in time by something which antecedes, in conformity with a rule--in other words, the relation of cause and effect--is the condition of the objective validity of our empirical judgements in regard to the sequence of perceptions, consequently of their empirical truth, and therefore of experience. |
| The principle of the relation of causality in the succession of phenomena is therefore valid for all objects of experience, because it is itself the ground of the possibility of experience. |
| Here, however, a difficulty arises, which must be resolved. |
| The principle of the connection of causality among phenomena is limited in our formula to the succession thereof, although in practice we find that the principle applies also when the phenomena exist together in the same time, and that cause and effect may be simultaneous. |
| For example, there is heat in a room, which does not exist in the open air. |
| I look about for the cause, and find it to be the fire, Now the fire as the cause is simultaneous with its effect, the heat of the room. |
| In this case, then, there is no succession as regards time, between cause and effect, but they are simultaneous; and still the law holds good. |
| The greater part of operating causes in nature are simultaneous with their effects, and the succession in time of the latter is produced only because the cause cannot achieve the total of its effect in one moment. |
| But at the moment when the effect first arises, it is always simultaneous with the causality of its cause, because, if the cause had but a moment before ceased to be, the effect could not have arisen. |
| Here it must be specially remembered that we must consider the order of time and not the lapse thereof. |
| The relation remains, even though no time has elapsed. |