But if a man knowingly does acts which must make him unjust, he will be voluntarily unjust; though it does not follow that, if he wishes it, he can cease to be unjust and be just, any more than he who is sick can, if he wishes it, be whole. And it may be that he is voluntarily sick, through living incontinently and disobeying the doctor. At one time, then, he had the option not to be sick, but he no longer has it now that he has thrown away his health. When you have discharged a stone it is no longer in your power to call it back; but nevertheless the throwing and casting away of that stone rests with you; for the beginning of its flight depended upon you. 55

Just so the unjust or the profligate man at the beginning was free not to acquire this character, and therefore he is voluntarily unjust or profligate; but now that he has acquired it, he is no longer free to put it off.