It Takes Both

Since, then, the habits of the speculative intellect do not perfect the appetitive part, nor affect it in any way, but only the intellective part; they may indeed be called virtues in so far as they confer aptness for a good work, viz. the consideration of truth (since this is the good work of the intellect): yet they are not called virtues in the second way, as though they conferred the right use of a power or habit. For if a man possess a habit of speculative science, it does not follow that he is inclined to make use of it, but he is made able to consider the truth in those matters of which he has scientific knowledge: that he make use of the knowledge which he has, is due to the motion of his will. Consequently a virtue which perfects the will, as charity or justice, confers the right use of these speculative habits. And in this way too there can be merit in the acts of these habits, if they be done out of charity: thus Gregory says (Moral. vi) that the “contemplative life has greater merit than the active life.”

(source: Summa Theologica II.I.57.1)