Since therefore Happiness is to be gained by means of certain acts, we must in due sequence consider human acts, in order to know by what acts we may obtain Happiness, and by what acts we are prevented from obtaining it. But because operations and acts are concerned with things singular, consequently all practical knowledge is incomplete unless it take account of things in detail. The study of Morals, therefore, since it treats of human acts, should consider first the general principles; and secondly matters of detail.
In treating of the general principles, the points that offer themselves for our consideration are (1) human acts themselves; (2) their principles. Now of human acts some are proper to man; others are common to man and animals. And since Happiness is man's proper good, those acts which are proper to man have a closer connection with Happiness than have those which are common to man and the other animals. First, then, we must consider those acts which are proper to man; secondly, those acts which are common to man and the other animals, and are called Passions. The first of these points offers a twofold consideration: (1) What makes a human act? (2) What distinguishes human acts?
And since those acts are properly called human which are voluntary, because the will is the rational appetite, which is proper to man; we must consider acts in so far as they are voluntary.
First, then, we must consider the voluntary and involuntary in general; secondly, those acts which are voluntary, as being elicited by the will, and as issuing from the will immediately; thirdly, those acts which are voluntary, as being commanded by the will, which issue from the will through the medium of the other powers.
And because voluntary acts have certain circumstances, according to which we form our judgment concerning them, we must first consider the voluntary and the involuntary, and afterwards, the circumstances of those acts which are found to be voluntary or involuntary. Under the first head there are eight points of inquiry:
(1) Whether there is anything voluntary in human acts?
(2) Whether in irrational animals?
(3) Whether there can be voluntariness without any action?
(4) Whether violence can be done to the will?
(5) Whether violence causes involuntariness?
(6) Whether fear causes involuntariness?
(7) Whether concupiscence causes involuntariness?
(8) Whether ignorance causes involuntariness?