its existence depends on an efficient cause. Thus, giving its existence precedence over its nonexistence is not like tipping one pan of a balance rather than the other, or singling out one time rather than another for something to come into being. In those cases, one thing is given precedence over its like without a determining factor: the event bears the same relation to either time, and the tipping of the balance bears the same relation to either pan. This differs from existence and nonexistence in relation to a contingent thing, for the preponderance of existence is not like the preponderance of nonexistence.

This is further clarified by the fact that what determines the existence of a contingent thing is not what determines its nonexistence, nor is it like it or of the same kind. What determines existence is an existing efficient cause, whereas what determines nonexistence is the nonexistence of the efficient cause. Existence is not nonexistence, nor is it like it or of the same kind. Thus, what determines one of the two alternatives for a contingent thing is not what determines the other, nor is it like it or of the same kind; nor can this be so in its case. By contrast, the factor that tips one pan of a balance, or singles out one time rather than another for something to come into being, may be the very same factor that favors the other, owing to a change in its properties, or it may be something of the same kind as the other factor.

Likewise, favoring the other attributes of temporally originated and contingent things over their alternatives is not like favoring existence over nonexistence. Rather, it is closer to favoring one time over another—for example, assigning a thing one magnitude rather than another, one quality rather than another, or one place rather than another, and so forth.

For this is closer to assigning it one time rather than another than to assigning it existence rather than nonexistence.