Aristotle, Nicomachean Ethics
H. Rackham, Ed.

Indeed the fact that an offence was committed in ignorance is itself made a ground for punishment, in cases where the offender is held to be responsible for his ignorance; for instance, the penalty is doubled if the offender was drunk,¹ because the origin of the offence was in the man himself, as he might have avoided getting drunk, which was the cause of his not knowing what he was doing. Also men are punished for offences committed through ignorance of some provision of the law which they ought to have known, and might have known without difficulty;