Over against any cognition, there is an unknown but knowable reality; but over against all possible cognition, there is only the self-contradictory. In short, cognizability (in its widest sense) and being are not merely metaphysically the same, but are synonymous terms.
Charles Sanders Peirce (1991). “Peirce on Signs: Writings on Semiotic”, p.50, UNC Press Books
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