Note 108 — Chapter X · SOPHISTICI ELENCHI.

Soph. El. xx. p. 177, a. 33-b. 9. οὐ πάντες οἱ ἔλεγχοι παρὰ τὸ διττόν, καθάπερ τινές φασιν.

This is another of the evidences showing that there were theorists prior to Aristotle on logical proof; and that his declaration of originality (in the concluding chapter of Sophist. Elenchi) must be taken with reserve.