We are reflecting only on what is fundamental in the determination of the essentiality of the essence, as it was stated once and for all in the Platonic-Aristotelian philosophy and became normative for posterity. That is, we are reflecting on what we ourselves ordinarily mean–even if in a very indeterminate way–when we speak about the “essence” of a thing. Insofar as we are successful in determining more precisely what we mean by essence we will also be capable of examining more exactly how the essence of something–e.g., the essence of truth–is posited, grasped, and founded, and what sort of foundation belongs to truth itself, according to its essence.
The first characterization Aristotle brings up with regard to the essence is that it contains the universal–e.g., the essence table is that which is common to all individual tables and therefore in an assertion about them is valid for all tables. Plato had already characterized the essence as what is common over and against the particularizations and had designated it with the name τὸ κοινόν. Ever since then, this characterization of the essence as the universal has remained the most usual one. But it is also in fact the most superficial, for no extended deliberation is needed to see that the characterization of the essence as κοινόν, as what is common to many, is not sufficient. The essence of the table is not the essence because it is valid for many particular tables, real or possible, but the reverse: only insofar as it is the essence can it apply to the individual tables. The character of the κοινόν cannot be the genuinely distinctive mark of the essence but is only a possible consequence of the essence. We must say “possible,” because if we ask about the essence of Plato or of Frederick the Great, then we are certainly seeking the essence of these individual men, but here it is the essence of something which is, by its very “nature,” precisely singular and unique–a kind of essence that precisely excludes being valid for many.
In this way it is clear that what is essential in the essence cannot be the κοινόν but that which admits, or demands, that the essence be valid for the many individuals. But what is that? What