§25. The Time in which a Change takes place.
As the Principle of Sufficient Reason of Becoming is exclusively applicable to changes, we must not omit to mention here, that the ancient philosophers had already raised the question as to the time in which a change takes place, there being no possibility of it taking place during the existence of the preceding state nor after the new one has supervened. Yet, if we assign a special time to it between both states, a body would, during this time, be neither in the first nor in the second state: a dying man, for instance, would be neither alive nor dead; a body neither at rest nor in movement: which would be absurd. The scruples and sophistic subtleties which this question has evoked, may be found collected together in Sextus Empiricus "Adv. Mathem." lib. ix. 267-271, and "Hypat." iii. c. 14; the subject is likewise dealt with by Gellius, 1. vi. c. 13—Plato[1] had disposed somewhat cavalierly of this knotty point, by maintaining that changes take place suddenly and occupy no time at all; they occur, he says, in the ἐξαίφνης, (in repentino), which he calls an ὰτοπος φύσις, ἐν χρόνῳ ούδὲν ούσα; a strange, timeless existence (which nevertheless comes within Time).
It was accordingly reserved for the perspicacity of Aristotle to clear up this difficult point, which he has done profoundly and exhaustively in the sixth Book of Physics, chap, i.-viii. His proof that no change takes place suddenly (in Plato's ἐξαίφνης) , but that each occurs only gradually and therefore occupies a certain time, is based entirely upon the pure, a priori intuition of Time and of Space; but it is also very subtle. The pith of this very lengthy demonstration may, however, be reduced to the following propositions. When we say of objects that they
- ↑ Plato, "Parmenides," p. 138, ed. Bip.
