To Charles Augustus Strong
22 Beaumont St.
Oxford, England. Feb. 26. 1918
Your dislike of essences seems to me very curious: I can’t attribute it to anything but a sort of traditional dread of Platonism as if it were Popery. My essences are akin to Platonic ideas, certainly: but when you say that you don’t understand the principle by which they are selected, you assimilate them to Platonic ideas just in the respect in which they are opposed to them. Essences are not selected in their own being: to select is evidently to leave something out: but what is left out must differ in character from what is chosen: therefore, it too has a character, or is an essence.
Platonic Ideas were selected ab extra by an inversion: natural types and moral ideals were projected into powers: and these essences, having alleged power over the world, were the Ideas. But that is physics or metaphysics or cosmology: essences are absolutely infinite and packed close, like points in space. A selection among them is a matter of partial survey, not of exclusive being in what is selected. Exclusive being would be existence: but among essences no one has any inherent emphasis not found in others.
On the other hand no essence is self-contradictory. A round square is not an essence–at least not in the sphere of geometry. If you say the phrase has a certain import and character–it is a typical self-contradiction–that proves that “round square” is the essence of a sort of accident in human discourse, viz. the use of words with divergent meanings as if they were compatible, until the connotations are felt to clash and the effort collapses. There is no self-contradiction in this experience of contradiction in terms or of diversity of essences; which is what the attempt to intuit a round square amounts to.
From The Letters of George Santayana: Book Two, 1910-1920. Cambridge, MA: The MIT Press, 2001.
Location of manuscript: Rockefeller Archive Center, Sleepy Hollow NY