Catechism of the Summa (21)

 VI. OF WHAT IS IMPLIED IN A HUMAN ACT FOR IT TO BE A GOOD MERITORIOUS ACT, OR A BAD DEMERITORIOUS ACT; AND OF MERIT AND DEMERIT IN GENERAL

(A)

Is it possible to say by what means man on earth and in this life can prepare himself, by way of merit, to receive from God some day in token of reward the beatific vision in which consists man's eternal happiness?

Yes, this he can merit solely by his acts 

Of what kind of acts is there question?

Of virtuous acts.

What is meant by "acts of virtue"?

They are those "acts which man performs by his own free will in conformity with God's will under the action of grace" 

What is necessary that man's acts should proceed from his will?

It is necessary that he perform them spontaneously and with the knowledge that he is their cause 

What is meant by saying that he must perform them spontaneously?

It is meant that he must perform them without constraint or force 

How can man be coerced or forced to do something against his will?

Man can be coerced or forced to do something against his will in two ways: by violence and by fear 

What is understood by violence?

By violence is understood a force exterior to man which fetters his members and impedes him from acting as he wills, or makes him do exteriorly what his will rejects

What is understood by fear?

By fear is understood an interior movement which makes man will a thing he would not otherwise will, but to which he consents in the present circumstances in order to avoid some evil that threatens 

Is that which one does under violence wholly involuntary?

Yes, that which one does under exterior violence is wholly involuntary 

Why under "exterior" violence?

Because sometimes the word "violence" is taken to signify the internal movement of anger.

In this case and in the case of other interior movements which excite or incline the will may one also speak of involuntariness?

No, in these divers cases one may not speak of involuntariness unless perchance these interior movements be so vehement as to deprive man of the use of his reason

And when one acts through fear, is the act also involuntary?

When one acts through fear the act is voluntary, but with it there is an admixture of involuntary in this sense, that that which is done is indeed willed, but it is willed with reluctancy and by reason of some evil from which man shrinks 

(B)

It has also been said that for man's acts to be voluntary they must be done with knowledge of what is being done?

Yes; and this means that if one performs an act, with out the knowledge of what one is really doing, the act done is not voluntary

Is such an act then involuntary?

Yes, provided that if one knew the true facts, one would not have performed the act 

Can that which one does or which one does not owing to ignorance or to some error, be nevertheless sometimes voluntary?

Yes; it is always so if one is responsible for one's ignorance or one's error 

And when is one responsible for one's ignorance or one error?

When one wills these directly, or when they are the outcome of culpable negligence 

(C)

Must not one take into account the circumstances which accompany a human act, since upon them depends so much the character of the act?

Yes; and nothing is more important than the weighing of the circumstances of a human act in order to appreciate its true value 

Is it possible to enumerate these circumstances?

Yes, these circumstances are those of person, of object, or of effect produced, of place, of motive, of the means employed, and of time 

What is meant by these different circumstances?

These different circumstances bear on the character or condition of the person who acts, on what he does, or on what results from his act, on the place where he does the act, on the end for which he acts, on those things which he uses as means, and on the time when he acts 

Which is the most important of these circumstances?

It is the motive for which a person acts or the end which he has in view when he acts 

Is it always the will which produces human acts?

Yes, it is always the will; sometimes the will only; at other times it is some other faculty or even the exterior members of the body, but always under the impulse and by order of the will