Aristotle states that coming to be is not a random process but rather involves contraries. If things come to be in this way, according to Aristotle, nothing that exists naturally is affected by just “any old thing”, unless coincidence is considered. It is contraries, or opposites in nature, that account for the coming to be and passing away of all things.
The example that Aristotle uses to illustrate this point is that of paleness versus musicality. He says that something cannot come to be pale from being musical, unless by coincidence. In this way, something also cannot come to be musical from being pale. Rather, a man comes to be musical from being unmusical and something comes to be pale from being not-pale. These contraries can be applied to all instances of coming to be, even such that of a house. A house starts out as individual bricks, disorderly, and only comes to be a house once they are put in perfect arrangement, thus becoming orderly from a state of being disorderly.
Aristotle’s theory of contraries is troublesome to me when considering the contrary states of being alive and being dead. If a person comes to be dead from a state of being alive, and alive from a state of being dead, that would require a person that is not alive to come back to life again. This idea puzzles me and makes me wonder, if Aristotle was right, if people are ever really dead at all.