and that his essence is conceived by means of them and by nothing else, yet one cannot know that his essence is conceived only through them until the essence itself is already known.

If it is objected, “Merely conceiving animality and rationality entails conceiving man,” we reply: Simply forming that concept does not lead one to know that this is man until he knows that man is composed of these two qualities and nothing besides; and that, in turn, demands prior knowledge of man.

Furthermore, the bare utterance “rational animal,” when taken as a single term and not as the predicate of an implied subject, is no more than an isolated noun, and an isolated noun communicates no meaningful statement.

Thus, if someone claims that whoever conceives this term has thereby conceived man—without producing any proof that it represents the very reality of man—he is like one who defines man as “laughing animal” and insists that this is man’s reality. Both assertions are claims without evidence.

This makes clear that the signification of a definition stands on the same footing as the signification of a name: it merely distinguishes the entity defined—the thing named—from everything else. A definition may, however, spell out in detail what the name conveys in a general way, and that detail varies with the attributes cited; it is not confined to some special set of attributes that exactly match the subject and are mutually necessary. It also shows that words, by themselves, do not convey the realities to one who has not already conceived them apart from the words; they merely alert and point the inattentive in their direction.

If it is said, “The conception of the thing rests on conceiving its essential attributes, not on knowing that they are essential, and those attributes can indeed be conceived even if one does not know they are essential to it,” we reply: Grant that for the sake of argument; yet one must still distinguish between the essential attributes without which the essence cannot be conceived and the accidental attributes that can be conceived without them. That distinction is impossible unless the essence—composed of its essential attributes—is already known; and the essence is not known.