Plato, Protagoras 350e-351b
“I do not here or anywhere else claim that the powerful are strong, but instead that the strong are powerful. For I believe that power and strength are not the same thing. One of them—power—comes from knowledge, or from madness, or anger; strength, however, comes from nature and the nourishing of the body.
So, for the first quality, daring and bravery are not the same thing. It can be the case that the brave are in fact daring, but the daring are not all brave. For boldness also comes to men from some type of skill or rage or madness, just like power, whereas bravery comes from nature and the nurturing of the mind.”
ἐγὼ δὲ οὐδαμοῦ οὐδ᾿ ἐνταῦθα ὁμολογῶ τοὺς δυνατοὺς ἰσχυροὺς εἶναι, τοὺς μέντοι ἰσχυροὺς δυνατούς· οὐ γὰρ ταὐτὸν εἶναι δύναμίν τε καὶ ἰσχύν, ἀλλὰ τὸ μὲν καὶ ἀπὸ ἐπιστήμης γίγνεσθαι, τὴν δύναμιν, καὶ ἀπὸ μανίας γε καὶ θυμοῦ, ἰσχὺν δὲ ἀπὸ φύσεως καὶ εὐτροφίας τῶν σωμάτων. οὕτω δὲ κἀκεῖ οὐ ταὐτὸν εἶναι θάρσος τε καὶ ἀνδρείαν· ὥστε συμβαίνει τοὺς μὲν ἀνδρείους θαρραλέους εἶναι, μὴ μέντοι τούς γε θαρραλέους ἀνδρείους πάντας· θάρσος μὲν γὰρ καὶ ἀπὸ τέχνης γίγνεται ἀνθρώποις καὶ ἀπὸ θυμοῦ γε καὶ ἀπὸ μανίας, ὥσπερ ἡ δύναμις, ἀνδρεία δὲ ἀπὸ φύσεως καὶ εὐτροφίας τῶν ψυχῶν γίγνεται.