31. Vincible ignorance makes an act less voluntary and less sinful: (a) when the ignorance is not affected, for the voluntariness is measured by the knowledge, and knowledge here is lacking; (b) when the ignorance, though affected, was fostered only through fear that knowledge might compel a stricter way of life; for such a state of mind seems to show that one would not act the same way if one had knowledge.
32. Like to ignorance are the following: (a) error, which is a judgment not in agreement with the facts (e.g., Balbus, a young child, thinks stealing is lawful, because older persons are represented as stealing in the moving pictures); (b) forgetfulness, which is ignorance of what was once known (e.g., Titus made a study of his duties as a Catholic when he was young, but at present what he does not know about those duties is not inconsiderable); (c) inadvertence, which is a lack of attention to what is being done (e.g., Caius, who is absent-minded, sometimes gets his hair cut and goes away without paying, or takes money that does not belong to him).
33. The principles and conclusions given above with regard to ignorance will apply also to error, forgetfulness and inadvertence; for in all these cases the lack of actual knowledge at the moment an act is done, is either willed or not willed, and accordingly the act itself is either voluntary or not voluntary. In the examples mentioned above, Balbus does not will the guilt of theft, since he does not know it; but his elders do will that guilt, because they should know it. Titus is responsible for neglecting his duties, if he has forgotten them through his own neglect of them or other fault; otherwise, he is not responsible. Caius’ inattention is involuntary, if due to mental concentration or distraction, and if it is not desired by him; it is voluntary, if he is aware of it and cultivates it, or if he does not try to be more attentive to his duties.
34. Consent Requisite for a Human Act.—To be human, an act must proceed not only from knowledge, but also from inclination; that is, it must be voluntary. Three things are necessary in order that an act be voluntary: (a) it must be agreeable to an internal principle, i.e., in most moral matters to the will. Hence, an act that is done against one’s will on account of external violence is not voluntary; (b) it must be caused by the will. Hence, a shower of rain is said to be agreeable to the gardener, but not voluntary since his will is not its cause; (c) it must be performed with a conscious purpose. Hence, natural acts (such as sleeping) and spontaneous acts (such as stroking one’s beard absent-mindedly) are not voluntary acts.
35. Kinds of Voluntary Acts.-(a) A voluntary act is free or necessary, according as one can or cannot abstain from it. The vision of God in heaven is voluntary to the blessed, since they look at Him knowingly and gladly; but it is not free, since they cannot avert their gaze from that which makes them blessed. The love of God on earth is voluntary, since chosen; but it is also free, since man is able to turn away from God.
(b) An act is perfectly or imperfectly voluntary, according as the deliberation and consent that precede it are full or only partial.
(c) An act is said to be simply—that is, absolutely—voluntary, when it is wished under circumstances that exist here and now, although in itself, apart from those circumstances, it is not wished. It is said to be voluntary under a certain aspect, when it is desired for itself, but not under existing conditions. Thus, if an arm needs to be amputated to save life, the amputation is absolutely voluntary, while the preservation of the arm is voluntary only in a certain respect. Hence, an act is voluntary simply or absolutely when one chooses it, all things considered; it remains involuntary under a certain respect, inasmuch as the choice is made with reluctance.
(d) An act is voluntary in itself or directly, when it is desired in itself for its own sake (i.e., as an end), or for the sake of something else (i.e., as a means). It is voluntary in its cause or indirectly, when it is not desired in itself, either as a means or an end, but is foreseen as the result of something else that is intended. Examples: Titus quarrels with his neighbors, at times because he likes to quarrel, and at other times because he wishes to make them fear him; hence, his quarrels are directly voluntary. Caius is a peaceful man who dislikes quarreling; but he likes to drink too much occasionally, although he knows that he always quarrels when he is under the influence of liquor. Thus, his quarrels are indirectly voluntary.
36. An act is voluntary in its cause in two ways: (a) approvingly (physically and morally voluntary in cause), when one is able and obliged not to perform the act that is its cause (e.g., the quarrels of Caius mentioned above are approved implicitly by him, since he could and should prevent the intoxication which is their cause); (b) permissively (physically voluntary in cause), when one is not able or not obliged to omit the act that is its cause (see 94 sqq.). Examples: Balbus, in order to make a living, has to associate with persons of quarrelsome character, and as a result often hears shocking disputes. Titus, a military commander, orders an enemy fortification to be bombarded, although he knows that this will involve the destruction of other property and the unavoidable killing of some non-combatants or neutrals. Caius writes a book whose purpose and natural result is edification, but he foresees that evil-minded persons will misunderstand it and take scandal.
37. Omissions, as well as acts, may be voluntary. (a) Thus, they are directly voluntary, when they are willed as an end or as a means to an end. Example: Titus fails to reprove the disorders of those in his charge because he likes disorder, or because it illustrates his theory that everyone should go through an evolution from roughness to refinement. (b) They are indirectly voluntary, when their cause is willed with approval or permitted with disapproval. Example: Balbus does not like to miss Mass, but he fails to rise from bed when he hears the church bell ringing, and as a result does not get to church. If his failure to get up was due to laziness, the omission of Mass was approved by Balbus; if it was due to illness, the omission was only permitted.