We now turn to a discussion of the individual's responsibility for his acts and the voluntary nature of moral purpose. As already shown, virtue or moral excellence is a matter of feeling and action. Since a man is praised or blamed only for things done voluntarily, it is essential to distinguish between voluntary and involuntary actions.
Involuntary actions are those performed under compulsion or as a result of ignorance. An act is compulsory if it originates in an external cause and the agent (doer of the act) contributes nothing to it (e.g., this is the case when the captain of a ship is forced off course by adverse winds).
The situation is not always this clear. Some acts involve a mixture of voluntary and involuntary (e.g., when a man obeys a tyrant's command to commit an immoral act in order to protect his loved ones). Such acts in the end must be classified as being more akin to voluntary, since the man freely chooses between alternatives. Actions cannot be judged only according to abstract moral principles, but must be evaluated in regard to the particulars of the given situation and there are some things which a good man ought not to do under any circumstances.
Acts committed in ignorance are not considered to be voluntary, but a distinction must be drawn between an act done through ignorance which is subsequently regretted by the agent (classified as an involuntary act), and such an act which is not regretted (classified as a non-voluntary act). There is also a distinction between an act due to ignorance and an act done in ignorance. A drunken man may act ignorantly, but his ignorance is due to the alcohol he has consumed and not to his own lack of knowledge; in this sense his act may be non-voluntary.
One might claim that an evil man is ignorant of the difference between right and wrong, with the result that his evil deeds due to this ignorance are non-voluntary and not reprehensible. This is a serious error. Involuntary acts are the result of ignorance in a particular situation, but "universal" ignorance (i.e., ignorance of what is right and wrong) can never be condoned. Such ignorance does not make an act involuntary, but it does make it evil. The only ignorance for which an agent can be forgiven is ignorance of the particular circumstances attached to his act. So long as an act originates in the agent and he understands the circumstances in which he acts, his act is voluntary and he is responsible for its consequences.
Aristotle's conception of the voluntary nature of moral purpose is best illustrated by a simple syllogism, in which the major premise is taken to represent "universal" ignorance and the minor premise to represent "particular" ignorance. Where the major premise is that taking another person's property without his knowledge or consent is stealing and the minor premise is that a particular thing is another person's property, it can be proved that removing that particular thing from a given place is stealing. According to Aristotle, ignorance of the major premise results in an evil act, but ignorance of the minor premise results in an involuntary act, i.e., it is not stealing if one does not know the property belongs to someone else. It is a serious moral flaw if a man does not understand what stealing is, but it is possible to know that stealing is wrong and still take someone else's property in ignorance. This is the sort of ignorance of particular circumstances that results in an involuntary act for which one is not morally responsible.
For an act to be voluntary, one must know: (a) who the agent is, (b) what he is doing, (c) what person or thing is affected, (d) the means being used, (e) the result intended by the action, (f) the manner in which the agent acts. No one can be ignorant of all these factors, especially the first since every agent knows his own identity, but it is possible to be ignorant of some. For example, one may not know all the consequences of his act (b), he may mistake one person or thing for another (c), he may mistake a dangerous weapon for a harmless tool (d), he might try to save someone's life by giving him a drink that is actually harmful (e), he might strike someone too hard and injure him (f). In all these areas genuine ignorance is possible. In any given situation, obviously, some factors will be more important than others.
Since an action is involuntary when performed under constraint or through ignorance, a voluntary action can be defined as one in which the initiative lies with the agent and in which the agent knows the particular circumstances in which his action is performed. Acts due to passion or desire are classified as voluntary, on the grounds that irrational emotions are as much a part of human beings as reason, and that actions which spring from them are as much a man's responsibility as those he performs after a process of intellectual reasoning.