2.19.1 to 2.19.12

πρῶτον μὲν οὖν περὶ δυνατοῦ καὶ ἀδυνάτου λέγωμεν. ἂν δὴ τὸ ἐναντίον ᾖ δυνατὸν ἢ εἶναι ἢ γενέσθαι, καὶ τὸ ἐναντίον δόξειεν ἂν εἶναι δυνατόν, οἷον εἰ δυνατὸν ἄνθρωπον ὑγιασθῆναι, καὶ νοσῆσαι· ἡ γὰρ αὐτὴ δύναμις τῶν ἐναντίων ᾗ ἐναντία. καὶ εἰ τὸ ὅμοιον δυνατόν, καὶ τὸ ὅμοιον· καὶ εἰ τὸ χαλεπώτερον δυνατόν, καὶ τὸ ῥᾷον· καὶ εἰ τὸ σπουδαῖον καὶ καλὸν γενέσθαι δυνατόν, καὶ ὅλως δυνατὸν γενέσθαι· χαλεπώτερον γὰρ καλὴν οἰκίαν ἢ οἰκίαν εἶναι. καὶ οὗ ἡ ἀρχὴ δύναται γενέσθαι, καὶ τὸ τέλος· οὐδὲν γὰρ γίγνεται οὐδʼ ἄρχεται γίγνεσθαι τῶν ἀδυνάτων, οἷον τὸ σύμμετρον τὴν διάμετρον εἶναι οὔτʼ ἂν ἄρξαιτο γίγνεσθαι οὔτε γίγνεται. καὶ οὗ τὸ τέλος, καὶ ἡ ἀρχὴ δυνατή· ἅπαντα γὰρ ἐξ ἀρχῆς γίγνεται. καὶ εἰ τὸ ὕστερον τῇ οὐσίᾳ ἢ τῇ γενέσει δυνατὸν γενέσθαι, καὶ τὸ πρότερον, οἷον εἰ ἄνδρα γενέσθαι δυνατόν, καὶ παῖδα (πρότερον γὰρ ἐκεῖνο γίγνεται), καὶ εἰ παῖδα, καὶ ἄνδρα (καὶ ἀρχὴ γὰρ ἐκείνη). καὶ ὧν ἢ ἔρως ἢ ἐπιθυμία φύσει ἐστίν· οὐδεὶς γὰρ ἀδυνάτων ἐρᾷ οὐδὲ ἐπιθυμεῖ ὡς ἐπὶ τὸ πολύ. καὶ ὧν ἐπιστῆμαί εἰσι καὶ τέχναι, δυνατὸν ταῦτα καὶ εἶναι καὶ γίγνεσθαι. καὶ ὅσων ἡ ἀρχὴ τῆς γενέσεως ἐν τούτοις ἐστὶν ἃ ἡμεῖς ἀναγκάσαιμεν ἂν ἢ πείσαιμεν· ταῦτα δʼ ἐστὶν ὧν κρείττους ἢ κύριοι ἢ φίλοι. καὶ ὧν τὰ μέρη δυνατά, καὶ τὸ ὅλον, καὶ ὧν τὸ ὅλον δυνατόν, καὶ τὰ μέρη ὡς ἐπὶ τὸ πολύ· εἰ γὰρ πρόσχισμα καὶ κεφαλὶς καὶ χιτὼν δύναται γενέσθαι, καὶ ὑποδήματα δυνατὸν γενέσθαι, καὶ εἰ ὑποδήματα, καὶ πρόσχισμα καὶ κεφαλίς καὶ χιτών. καὶ εἰ τὸ γένος ὅλον τῶν δυνατῶν γενέσθαι, καὶ τὸ εἶδος, καὶ εἰ τὸ εἶδος, καὶ τὸ γένος, οἷον εἰ πλοῖον γενέσθαι δυνατόν, καὶ τριήρη, καὶ εἰ τριήρη, καὶ πλοῖον. καὶ εἰ θάτερον τῶν πρὸς ἄλληλα πεφυκότων, καὶ θάτερον, οἷον εἰ διπλάσιον, καὶ ἥμισυ, καὶ εἰ ἥμισυ, διπλάσιον.