Aristotle (Nicomachean Ethics): For the things we have to learn before we can do them, we learn by doing them, e.g. men become builders by building and lyrepla

Aristotle (Nicomachean Ethics): For the things we have to learn before we can do them, we learn by doing them, e.g. men become builders by building and lyreplayers by playing the lyre; so too we become just by doing just acts, temperate by doing temperate acts, brave by doing brave acts. This is confirmed by what happens in states; for legislators make the citizens good by forming habits in them, and this is the wish of every legislator, and those who do not effect it miss their mark, and it is in this that a good constitution differs from a bad one.