“[T]he vice of a thing seems to consist in its not being disposed in a way befitting its nature.”
—St. Thomas Aquinas, Summa Theologiae I-II, q. 71, a. 1
Are you a vicious person? The answer to this question depends on whether you have vice. But what is vice?
Perhaps it’s best to contrast it with virtue. Where virtue is an enduring disposition, or habit, to perform good human acts—acts that are befitting our nature as human beings, vice is an enduring disposition, or habit, to perform bad human acts—acts that are not befitting our nature as human beings (ST I-II, q. 71, a. 1).
For example, there’s a difference between a child who has a moment of weakness and steals for the first time a piece of candy from the grocery store and a child who has been doing it for several years. The first child doesn’t have a built-in readiness to steal but the second one does. For the first child it’s a bit difficult for him to bring himself to take the candy. The second child, on the other hand, has no problem with it. He doesn’t think twice about it and does it with ease. The first child doesn’t have a vice for thievery whereas the second child does.
Now, vice is not merely an enduring disposition (readiness) to perform a bad human act. It’s also an enduring disposition (readiness) to omit a good human act that one is bound to perform. A cop, for example, is bound to do the work of policing. If he repeatedly lets bad guys go without trying to stop them, he will develop an enduring disposition to omit his duty to do the work of a policeman. Such an enduring position to easily omit his duty would be a vice.
So, to answer the question of whether you have vice, you might ask yourself, “Are some sins easier for me to commit than others?” If you find yourself committing a sin with ease, it’s likely you’re doing so in virtue of a vice. The good news, however, is that you can get rid of the vice by repeatedly performing the good human acts that counter that vice and consequently develop the countering virtue.