§2.3αἱ δʼ ἀκροάσεις κατὰ τὰ ἔθη συμβαίνουσιν· ὡς γὰρ εἰώθαμεν οὕτως ἀξιοῦμεν λέγεσθαι, καὶ τὰ παρὰ ταῦτα οὐχ ὅμοια φαίνεται ἀλλὰ διὰ τὴν ἀσυνήθειαν ἀγνωστότερα καὶ ξενικώτερα· τὸ γὰρ σύνηθες γνώριμον.
Lectures are received according to habits; for we demand that things be spoken of in the way we are accustomed to, and what is contrary to this does not seem the same, but, owing to unfamiliarity, seems more unintelligible and strange; for the familiar is understandable.
ἡλίκην δὲ ἰσχὺν ἔχει τὸ σύνηθες οἱ νόμοι δηλοῦσιν, ἐν οἷς τὰ μυθώδη καὶ παιδαριώδη μεῖζον ἰσχύει τοῦ γινώσκειν περὶ αὐτῶν διὰ τὸ ἔθος.
How much strength the familiar has is shown by the laws, in which mythological and childish elements, owing to habit, have more influence than the knowledge about them.
οἱ μὲν οὖν ἐὰν μὴ μαθηματικῶς λέγῃ τις οὐκ ἀποδέχονται τῶν λεγόντων, οἱ δʼ ἂν μὴ παραδειγματικῶς, οἱ δὲ μάρτυρα ἀξιοῦσιν ἐπάγεσθαι ποιητήν.
Some people, then, do not accept speakers unless they speak mathematically; others, unless they speak by way of examples; others demand that a poet be brought in as a witness.
καὶ οἱ μὲν πάντα ἀκριβῶς, τοὺς δὲ λυπεῖ τὸ ἀκριβὲς ἢ διὰ τὸ μὴ δύνασθαι συνείρειν ἢ διὰ τὴν μικρολογίαν· ἔχει γάρ τι τὸ ἀκριβὲς τοιοῦτον, ὥστε, καθάπερ ἐπὶ τῶν συμβολαίων, καὶ ἐπὶ τῶν λόγων ἀνελεύθερον εἶναί τισι δοκεῖ.
Some want everything said with rigor, while rigor vexes others, either because they are unable to connect the arguments or because of its triviality; for rigor has something of this character, so that, just as in contracts, so in discussions it seems to some to be illiberal.
διὸ δεῖ πεπαιδεῦσθαι πῶς ἕκαστα ἀποδεκτέον, ὡς ἄτοπον ἅμα ζητεῖν ἐπιστήμην καὶ τρόπον ἐπιστήμης· ἔστι δʼ οὐδὲ θάτερον ῥᾴδιον λαβεῖν.
Hence one must be trained in how to accept each kind of argument, since it is absurd to seek at the same time knowledge and the method of knowledge; and it is not easy to acquire even one of the two.
τὴν δʼ ἀκριβολογίαν τὴν μαθηματικὴν οὐκ ἐν ἅπασιν ἀπαιτητέον, ἀλλʼ ἐν τοῖς μὴ ἔχουσιν ὕλην.
Mathematical rigor should not be demanded in all things, but only in those which do not have matter.
διόπερ οὐ φυσικὸς ὁ τρόπος· ἅπασα γὰρ ἴσως ἡ φύσις ἔχει ὕλην.
Therefore, this is not the method of natural science; for presumably all nature has matter.
διὸ σκεπτέον πρῶτον τί ἐστιν ἡ φύσις· οὕτω γὰρ καὶ περὶ τίνων ἡ φυσικὴ δῆλον ἔσται.
Hence we must first consider what nature is; for in this way it will also be clear what natural science is about.