Virtue also depends on ourselves. And so also does vice. For where we are free to act we are also free to refrain from acting, and where we are able to say No we are also able to say Yes; if therefore we are responsible for doing a thing when to do it right, we are also responsible for not doing it when not to do it is wrong, and if we are responsible for rightly not doing a thing, we are also responsible for wrongly doing it.

The Nicomachean Ethics (ed. Wordsworth Editions, 1996) - ISBN: 9781853264610