Whether a man is called unjust through doing an unjust thing?

❌ Objection 1 : It would seem that a man is called unjust through doing an unjust thing. For habits are specified by their objects, as stated above (FS, Question [54], Article [2]). Now the proper object of justice is the just, and the proper object of injustice is the unjust. Therefore a man should be called just through doing a just thing, and unjust through doing an unjust thing.

❌ Objection 2 : Further, the Philosopher declares (Ethic. v, 9) that they hold a false opinion who maintain that it is in a man's power to do suddenly an unjust thing, and that a just man is no less capable of doing what is unjust than an unjust man. But this opinion would not be false unless it were proper to the unjust man to do what is unjust. Therefore a man is to be deemed unjust from the fact that he does an unjust thing.

❌ Objection 3 : Further, every virtue bears the same relation to its proper act, and the same applies to the contrary vices. But whoever does what is intemperate, is said to be intemperate. Therefore whoever does an unjust thing, is said to be unjust.