Note 86 — Chapter VII · ANALYTICA POSTERIORA I.
Reading edition
Ibid. b. 35: δῆλον ὅτι καὶ εἰ ἦν αἰσθάνεσθαι τὸ τρίγωνον ὅτι δυσὶν ὀρθαῖς ἴσας ἔχει τὰς γωνίας, ἐζητοῦμεν ἂν ἀπόδειξιν, καὶ οὐχ (ὥσπερ φασί τινες) ἠπιστάμεθα· αἰσθάνεσθαι μὲν γὰρ ἀνάγκη καθ’ ἕκαστον, ἡ δ’ ἐπιστήμη τῷ τὸ καθόλου γνωρίζειν ἐστίν.
Euclid, in the 20th Proposition of his first Book, demonstrates that any two sides of a triangle are together greater than the third side. According to Proklus, the Epikureans derided the demonstration of such a point as absurd; and it seems that some contemporaries of Aristotle argued in a similar way, judging by the phrase ὥσπερ φασί τινες.