The Philosophical Review/Volume 1/Summary: Lechalas - Le temps, sa nature et sa mesure
When Leibniz said that time is the order of successions, he stated a terrible problem without solving it, for he did not tell us what successions are. For one who regards time as a reality independent of the things which pass, the question appears simple. But if time itself vanishes too, what do we mean by saying that one phenomenon has preceded or followed another? L. reduces the idea of time to that of occasional cause. In a group of facts, those which are the condition of the others are said to precede them, and vice versâ. The principle of mechanical determinism may be reduced to the statement that the states of a system of material points are determined, the one by the other, and that the determining states are called by definition anterior to the determined states, it being possible for each to be at the same time determined and determining, according as one considers its relation to the one or to the other of the different states. But it may be said that even here we employ the notion of simultaneity, which implies time. We must deepen the notion of simultaneity. A motionless world would be out of time, or rather time would not exist; yet we should speak of the simultaneity of the different relations existing between the parts of this world. As soon as one considers variable states, he is led to imagine dynamic states which enter into time; but one needs, as point of departure, only static states, and consequently does not fall into a vicious circle, as if he had really assumed at the start the temporal notion of simultaneity. This latter notion is clearly implied in phenomena like the mutual attraction of two bodies, for these stand to each other in the double relation of cause and effect. If there existed several series of phenomena absolutely independent of each other, these series would belong to different times, so that there would be neither simultaneity nor succession between two phenomena belonging respectively to these distinct series. Here one might ask if the existence of an omniscient intelligence would result in resolving into a unity these independent times. It cannot be denied that this doctrine comes into conflict with common sense, but such has been the fate of most thorough-going metaphysical theories. If time reduces itself in reality to the relation of occasional cause to effect, strictly speaking, it can admit of no measure. All that one can do in the case of a series of phenomena united by this unique relation is to count these phenomena. But the most complete incoherence appears to prevail between the different series of motions. If this is true on the physical, much more is it true on the psychic, plane. The psychic life offers the most striking contradictions between that which one might consider as the numbers of states of consciousness of two men during the same time, these numbers not appearing in any way proportional to each other. But the inferior phenomena which are most intimately connected with the corporeal life, present certain divisions of a remarkable uniformity. Sleep and wakefulness divide our existence into periods singularly alike. From facts like this we are led to form groups of these states which are nearly regular, and to call them equal. Then the motions of the sun, which preside over these fundamental phenomena of our existence, furnish us with a means of making a division into equal parts as small as we please. This affirmation does not in any way depend upon the relative or absolute character of time. L.'s theory of the measure of time may be adopted independently of his hypothesis as to its true nature.