Note 43 — Chapter X · SOPHISTICI ELENCHI.

Ibid. p. 168, a. 40: οὐδ’ εἰ τὸ τρίγωνον δυοῖν ὀρθαῖν ἴσας ἔχει, συμβέβηκε δ’ αὐτῷ σχήματι εἶναι ἢ πρώτῳ ἢ ἀρχῇ, ὅτι σχῆμα ἢ ἀρχὴ ἢ πρῶτον τοῦτο.

Here we have Figure reckoned as an accident of Triangle. This is a specimen of Aristotle’s occasional laxity in employing the word συμβεβηκός. He commonly uses it as contrasted with essential, of which last term Mr. Poste says very justly (notes, p. 129):— “To complete the statement of Aristotle’s view, it should be added, that essential propositions are those whose predicate cannot be defined without naming the subject, or whose subject cannot be defined without naming the predicate.” Now figure is the genus to which triangle belongs, and triangle cannot be defined without naming its genus figure. But to include Genus as a predicable under the head of συμβεβηκός or Accident, is in marked opposition to Aristotle’s own doctrine elsewhere: see Topic. I. v. p. 102, b. 4; iv. p. 101, b. 17; Analyt. Post. I. ii. p. 71, b. 9; Metaphys. E. p. 1026, b. 32. It is a misfortune that Aristotle gave to this general head of Fallacy the misleading title of Fallacia Accidentia — παρὰ τὸ συμβεβηκός. When he gave this title, he probably had present to his mind only such examples as he indicates in Soph. El. v. p. 166, b. 32. Throughout the Topica and elsewhere, Genus is distinguished pointedly from συμβεβηκός, though examples occur occasionally in which the distinction is neglected. The two Fallacies called Accidentis and Consequentis, would both be more properly ranked under one common logical title — Supposed convertibility or interchangeableness between Subject and Predicate — εἰ τόδε ἀπὸ τοῦδε μὴ χωρίζεται, μηδ’ ἀπὸ θατέρου χωρίζεσθαι θάτερον (vii. p. 169, b. 8).