Likewise, each of two contraries is possible and can be brought about, whereas their conjunction is neither possible nor capable of being brought about.

Likewise, if a hungry man is presented with dishes of food, each sufficient for him, he may lawfully eat any one of them, but he may not eat them all until he becomes sick from overeating and dies.

Likewise, if someone says to another, “Take a slave from among my slaves, or a horse from among my horses,” he may lawfully take any one of them, but not all of them.

Thus, saying, “Each of these is permissible,” does not entail that they are permissible collectively.

The point is that the attributes possessed by each individual instance are of three kinds:

The first is an attribute that cannot be conceived as applying to the aggregate. It can therefore be neither affirmed nor denied of it.

The second is an attribute that can be conceived as applying to the aggregate. It may indeed hold true of it, as dependence on an agent holds true of the aggregate of contingent things and things that have come into being; and as marriage is lawful to each eligible woman separately, and to four together.

Or it may not hold true of it, as each individual event that has passed has an end, while their aggregate does not; and as marriage to either of two sisters is lawful, but marriage to both together is not.

The distinction between these cases is that if the judgment applying to the individuals rests on a characteristic also present in the aggregate, it applies to the aggregate as well. If it does not rest on such a characteristic, it need not apply to the aggregate. Thus, the contingency of that which has been brought into being, or its dependence on an agent, is established by virtue of its having come into being—a characteristic shared by both the individuals and the aggregate.

Likewise, the dependence of the contingent on what is not contingent is established