Full Idea
Since we must distinguish the substratum and the property whose nature is to be predicated of the substratum,..there is alteration when the substratum persists...but when nothing perceptible persists as a substratum, this is coming-to-be and passing-away.
Gist of Idea
If the substratum persists, it is 'alteration'; if it doesn't, it is 'coming-to-be' or 'passing-away'
Source
Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 319b08-16)
Book Reference
Aristotle: 'The Basic Works of Aristotle', ed/tr. McKeon,Richard [Modern Library Classics 2001], p.484
A Reaction
As usual, Aristotle clarifies the basis of the problem, by distinguishing two different types of change. Notice the empirical character of his approach, resting on whether or not the substratum is 'perceptible'.