The Commens Dictionary
Quote from ‘The Fourth Curiosity’
Coming to Essence, this in its epistemological force is that intelligible character which truly defines what a general or indefinite, that is, what an indeterminate monadic predicate primarily asserts, so that all else that it asserts is the necessary consequence of this epistemological essence. It is easy to state what the essences of artificial objects are: The essence of a stove is that it is intended to diffuse warmth. But as to the essence of natural objects, if they have any, we are unable as yet to give them. We are only able to state the essence of our common names for such things. The metaphysical essence is the intelligible element of the possibility of its Being, or so much of that as is not a mere consequence of the rest…
‘Essence’ (pub. 29.05.14-18:23). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from http://www.commens.org/dictionary/entry/quote-fourth-curiosity-2.