(a) if the habit is in a sense involuntary, i.e., caused by free acts but retracted by a sincere act of contrition, it diminishes or even takes away voluntariness. If the actual advertence to the act is imperfect, the voluntariety is diminished; if advertence is totally absent, all voluntariety is taken away. Thus a drunkard who retracts his habit and makes an act of true contrition may again fall into sin because of the acquired dispositions to drink. Then the sins are less voluntary or at times, owing to total lack of advertence, may be regarded solely as material sins. (b) if the habit is voluntary, i.e., acquired by free acts and not retracted, it increases the voluntariness in respect to the inclination to act. Should all advertence and deliberation be taken away, a rare occurrence, it diminishes the liberty of the act and consequently its morality as good or bad. Voluntariety, however, is not taken away entirely, since the habit itself was freely willed and hence acts flowing from it are voluntary in cause (see 35.). If sufficient advertence remains, the habit diminishes the freedom of the act owing to the impeding of reason; but this diminution of liberty is in accord with the will of the individual who freely contracted and conserves the habit to have facility in acting. Accordingly, absolutely speaking, a voluntary habit increases the voluntariety of acts caused by that habit and consequently increases their goodness or evil. Thus St. Thomas asserts that one who sins from habit sins from certain malice, i.e., not from ignorance or passion, but from the will’s own choice. 54. Natural propensities are inclinations that arise from bodily constitution or physical condition (e.g., a strong native attraction to temperance or to intemperance not acquired by frequent acts). Natural propensities have the same kind of influence on the willingness of an act as involuntary habits (see 53.). 55. Pathological states are diseases of the brain or nerves that react upon the intellect and the will, such as various kinds of neuroses and psychoses, hysteria and epilepsy. The influence of pathological states on the voluntariness of acts seems similar in kind to that ascribed to antecedent passion (see 48.). Caution must be observed in applying these principles to particular kinds of mental diseases.[1] [1] In doubt whether an act associated with a pathological state is free or not, the rule of moralists is lenient. When the act is sinful, it is not imputed as gravely sinful, for man is innocent until proven guilty. If the act is good, it is presumed voluntary and free and, consequently, meritorious. See Prummer, D.M., O.P., _Manuale Theologiae Moralis_ (Barcelona: Herder, 1946), I. n.93. 56. Two Kinds of Voluntary Acts.--Having discussed human or voluntary acts in general, we shall now indicate in particular the acts that are of this kind. There are two classes of voluntary acts: (a) those elicited by the will; (b) those commanded by the will.