Aristotle on Degrees of Proof and Exactitude

πεπαιδευμένου γάρ ἐστιν ἐπὶ τοσοῦτον τἀκριβὲς ἐπιζητεῖν καθʼ ἕκαστον γένος, ἐφʼ ὅσον ἡ τοῦ πράγματος φύσις ἐπιδέχεται· παραπλήσιον γὰρ φαίνεται μαθηματικοῦ τε πιθανολογοῦντος ἀποδέχεσθαι καὶ ῥητορικὸν ἀποδείξεις ἀπαιτεῖν.

For it belongs to an educated man to expect just so much exactness in each type of study which the nature of that study admits. To accept probable arguments from a mathematician is just as unreasonable as to expect rigorous demonstrations from an orator.

ARISTOTELIS. ETHICA NICOMACHEA I.3.4.