from a single standpoint, and it is impossible for the two to concur in truth or in falsehood, for the proposition that an existent is necessary in itself and the proposition that it is possible in itself can neither be simultaneously true nor simultaneously false.

So, if you define contradictories as two propositions that cannot both obtain and cannot both be absent, then these two fit that definition; yet they are not simply a case of affirmation and negation. Consequently, it is unsound to restrict the notion of contradiction—those pairs that cannot both obtain or both be absent—to affirmation and negation alone.

Accordingly, we now have two attributes that exclude and do not relinquish one another, and they fall outside the familiar fourfold divisions.

On this basis, anyone who considers death to be a positive ontological state might argue that the fact a thing is never devoid of either life or death belongs to this very category.