Section 1: Human Acts Defined

1. Man is composed of body and soul. His acts, to be truly human, must bear the mark of those faculties which distinguish him from the lower orders of creation, namely, understanding and free-will. A human act (actus humanus), in contradistinction to an act of man (actus hominis), is characterized by three essential qualities:—knowledge, voluntariness, and freedom. "All three are necessary to it, and, as necessary, they are called 'principles' of the human act.”¹

¹ M. Cronin, The Science of Ethics, Vol. I, p. 33. —Cfr. Gury, Compendium Theol. Mor., I, n. 1: "A human act is one which proceeds from man's deliberate will, or an act proceeding from a free will with advertence to moral goodness or evil. Thus a human act means the same as a moral act. Hence it differs from an act of man, which occurs in man, or is done by man, without any deliberation, such as indeliberate acts of concupiscence, or first-first movements, or acts of a man who is wholly distracted, dreaming, delirious, insane, drunk, or deprived of the use of reason in any manner."

2. A human act does not necessarily manifest itself externally (actus externus) but may be completed within the will (actus internus).

3. A human act need not be positive, but may consist in an omission, for freely to omit an act is as imputable to the will as to perform it. If an omission (omissio, actus omissus) is the result of culpable inadvertence or carelessness, it is voluntary in the cause (voluntarium in causa).

4. A human act, being the product of a finite creature, is not what the Scholastics call actus purus, i. e., it is not conceived and consummated simultaneously, but passes through a series of distinct periods of time. First an impression is made on the senses. This leads to a notion or concept, which is presented by the intellect as desirable to the will. As soon as the will consents, there is an actus internus. When this internal act sets the bodily powers in motion and becomes external, there results an actus externus. An act that has run through all these stages is called complete or perfect.²

² Cfr. Gury, Comp. Theol. Mor., I, n. 4, 3: "[The voluntary is distinguished as] perfect or imperfect, according as it is had with full knowledge and full consent, every resistance of the will being excluded, or with imperfect knowledge or imperfect consent or even with some resistance of the will. Hence this imperfect voluntary is twofold: 1° strictly imperfect, namely when full knowledge or full consent is lacking; 2° broadly imperfect, when the will indeed resists to some extent but remains free and consents absolutely."

READINGS. —St. Thomas, Summa Theol., 1a 2ae, qu. 18-20 (Rickaby, Aquinas Ethicus, Vol. I, pp. 55 sqq.). —St. Alphonsus, Theologia Moralis, l. V. (ed. Gaudé, Rome 1905 sqq., Vol. II, pp. 689 sqq.). —V. Cathrein, S.J., Moralphilosophie, 4th ed., Freiburg 1904, Vol. I, pp. 284 sqq.—L. Sacotte, Traité des Actes Humaines, Paris 1905. —J. Bucceroni, S.J., De Actibus Humanis, 3rd ed., Rome 1906.—M. Cronin, The Science of Ethics, Vol. I, pp. 30 sqq. —R. I. Holaind, S.J., Natural Law and Legal Practice, New York 1899, pp. 71 sqq. —Thos. Slater, S.J., A Manual of Moral Theology, Vol. I, pp. 1 sqq. —V. Frins, S.J., De Actibus Humanis, Vol. II, Freiburg 1904. —A. Sweens, Theologia Moralis Fundamentalis, Haaren 1910, pp. 31 sqq. —Sabetti-Barrett, S.J., Compendium Theologiae Moralis, 27th ed., pp. 10 sqq.