Virtue is not an act. Virtue is a habit. Virtue is an addiction.

The Virtue of Addiction is the habit of virtue.

Addiction is a condition of being devoted or given up to a practice or habit.
The root word is addicere which means to give assent. The root of assent (as + sentire) means to feel, to perceive the sense. Assent is acquiescence, consent, agreement, concurrence, permission or acceptance without protest or enthusiasm. It is an act of will. But it is an act of will that results in loss of will to perceive the sense of the will, to feel the will by feeling the presence and absence of will. It is a condition of being devoted to perceiving the sense of the voluntary and involuntary by feeling the experience.
Devoted means being dedicated, consecrated, vowed, very loyal, faithful. To devote oneself is to give up or apply oneself (one’s time, energy, etc.) to some purpose, activity or person. .
Addiction is to feel devoted to or to perceive the sense of a habit. The sense of something is the perception of its meaning, to perceive the cause and the effect, the essence, the principle, the fundamental truth.
Habit is a thing done often and done easily, it is doing something naturally, efficiently. It is an easy action. It is performing a certain act or behavior in a certain way and achieving a certain effect. It is an act or behavior that is acquired by practicing and through practice has become automatic. The root of automatic means self moving, self thinking. Automatic is moving, regulating, operating by itself, to be self acting, spontaneously. Spontaneous action is that which occurs or is done so naturally it seems to come without prompting or premeditation, automatically without conscious thought or volition. Habit is the self acting involuntarily, spontaneously and naturally.
To be addicted is to be the self acting habitually. It is the habit of acting habitually. It is perceiving the sense of acting automatically, spontaneously, involuntarily. It is learning how to act spontaneously. Addiction is the practice of habit to see the principles, the sense of free will, to see the whole of spontaneous will, to see the virtue of free will.
Practice is doing, performing something frequently and repeatedly in order to learn or acquire proficiency and skill. If an act is practiced, it is performed with the intent of making that act a habit, of making the act spontaneous.
To act is to do a thing, to perform or play a part in a play, to pretend to be, to behave like, to have an effect on (acids act on metals).
An act is a deed, a short performance, a thing done, an expression of a decree or decision, a part of a play, a piece of affected or feigned behavior, pretending to be something else. An act is not spontaneous. It is deliberate. It is calculated. An act implies deeper inconsistency, that the doing is not the being, that something is being overcome, coming from effort, is not authentic, is calculated, is forced, is not real, is not true.

Virtue is not an act. Virtue is a habit. Virtue is an addiction

The virtue of addiction is the habit of virtue.