present in knowledge or in minds and do not exist among concrete entities, and therefore have no reality whatsoever. Yet the person who utters this expression conceives within himself something that has no reality, as when one conceives of a human being who does not exist externally.

If you say, “The human being as such, without considering whether it exists in knowledge or in concrete reality,” I reply: Positing it without qualification or condition, as it is in itself, is also a mental construction. If something exists only as a mental construction, and you suppose that it is not a mental construction, you have combined two contradictories.

If you say, “I can conceive of a human being without qualification, without considering its existence in the mind or externally,” I reply: Conceiving of it without qualification, without restricting it to either mental or external existence, is one thing; conceiving of it subject to the exclusion of both mental and external existence is another.

In the first case, you have not conceived of all its necessary concomitants along with it. Conceiving of a thing without its necessary concomitants is possible. Thus, you may conceive of a human being without considering its existence or nonexistence, although it must be one or the other. This is conceiving of a thing without its necessary concomitants.

As for conceiving of it subject to the exclusion of both mental and external existence, this amounts to conceiving of the affirmation of both contradictories or the denial of both. It is like conceiving of a human being subject to the condition that it neither exists nor is nonexistent. Merely positing this in the mind makes its impossibility evident.

In the first case, however, conceiving of a thing without its necessary concomitant does not imply that it can exist in