Ethics, Part IV, Proposition 64
The knowledge of evil is an inadequate knowledge.
Proof
The knowledge of evil (IV. viii.) is pain, in so far as we are conscious thereof. Now pain is the transition to a lesser perfection (Def. of the Emotions, iii.) and therefore cannot be understood through man's nature (III. vi., and vii.); therefore it is a passive state (III. Def. ii.) which (III. iii.) depends on inadequate ideas; consequently the knowledge thereof (II. xxix.), namely, the knowledge of evil, is inadequate. Q.E.D.
Corollary
Hence it follows that, if the human mind possessed only adequate ideas, it would form no conception of evil.
Benedict de Spinoza, The Ethics (Ethica Ordine Geometrico Demonstrata), translated from the Latin by R. H. M. Elwes.
First published in The Chief Works of Benedict de Spinoza, vol. II (London: George Bell and Sons, 1884).
This translation is out of copyright in the United States, where it was published in 1884, and wherever the copyright term is the author's life plus 100 years or less; its translator died in 1892.
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