Summa Theologiae Moralis, vol. I: De Principiis

S. Th. I-II, q. 19, a. 3 and 4 ; 21, a. 1 ; 71, a. 6 ; 72, a. 4 and 8 ; 74, a. 7 ; 86, a. 1 and 2 ; 63, a. 2 ; De Malo, q. 2, a. 4 ; q 16, a. 2.

Having supposed an intrinsic discrimination of moral good and evil, we must now inquire into the foundations of this discrimination, and first into its subjective criterion or norm of morality; then into the objective criterion and ultimate foundation. About the first, two theses are laid down.

124. Thesis I. The nearer and intrinsic norm of morality is right human practical reason.

Explanation: It is called: 1) reason, and not only conscience, which is the rule of subjective morality of human acts, since here we are primarily concerned with the norm of objective morality: for conscience is particular reason, by which a definite person judges about the morality of such an act in particular and applies the law to a definite concrete case, whereas here we are more concerned with universal reason which judges about the morality of acts in general and enunciates the law, and is by essence common to all men; 2) right, i. e., judging conformably to the eternal law, from which it flows as from a fountain and rule of all good; for, as S. Thomas says, II Sent. d. 24, q. 3, a. 3, ad 3: « A corrupted reason is not reason, just as a false syllogism is not properly a syllogism, and therefore the rule of human acts is not any reason whatever, but right reason », which alone is able to order suitably toward the end and as is fitting;

3. is a nearer norm, rather than a proximate norm: for the latter is conscience, which applies the law to the concrete act, and so is the altogether proximate and immediate rule of acting, and with respect to it universal reason or law is already a remoter rule; and nevertheless this is the near rule with respect to the supreme and ultimate rule which is the eternal law of God himself;

4. and intrinsic: for reason is intrinsic to man, while the eternal law of God is extrinsic to him.

The thesis is proved 1° By facts: A moral action is to be called good, like any entity, when it reaches its end, or at least rightly and orderly tends toward its proper end. But it belongs to practical reason of man to discover what our ultimate end is, what means are necessary

The minor is proved:

a) Generally by experience;

b) Specially from the difference between rational and irrational nature (I-II, q. 91, a. 2): for it is evident that man rules himself and orders his acts toward an end; since therefore order is according to a rule, man must needs have implanted in him a rule by which he could rule himself and order his acts: which is nothing other than reason.

c) For just as speculative reason is by nature able to know the true, so practical reason is able to perceive the good (under the aspect of the true), i. e., the ordered relation of acts to the ultimate end, e. g., it dictates that blasphemy is evil as contrary to God the ultimate end, that intemperance is a sin because men thereby abuse

Briefly: The judgment of practical reason has as its object the fittingness and unfittingness of an act with an end. But the goodness of action resides in the relation of fittingness and subordination to the ultimate end of rational nature; malice in the relation of unfittingness. Therefore the judgment of practical reason

2° By reason drawn from S. Thomas, I-II, q. 90, a. 1: In each kind, that which is the principle is the measure and rule of that kind. Reason is the first principle of human acts, because it is its office to order toward the end, which is the first principle in matters of action. Therefore the rule and measure of human acts

125. Thesis II. The supreme and extrinsic norm and ultimate rule of morality is the reason of God, or the eternal law itself.

It is called: 1) the supreme norm, because morality depends more on this than on the near rule. For an effect depends more on the first cause than on the second cause, since the second cause does not act except by virtue of the first cause; whence that human reason is the rule of morality, this it has from the eternal law. Therefore moral good d

2. ultimate: the nearer norm is founded ultimately in the remote and fundamental norm or eternal law. Whence human reason is called the near, subordinate and regulated norm of morality; the eternal law the ultimate and supreme and regulating norm (q. 71, a. 6 ; q. 21, a. 1);

3. is the eternal law, i. e., the divine reason inasmuch as it conceives the ordering of all actions and orders them to the ultimate end, the will of God inasmuch as it necessarily wills this ordering to be observed by man, and the reason of God inasmuch as it commands this ordering and imposes it upon us.

It is proved: 1) Human reason is true or false according as it is conformed to truth or not: for it is cognitive, not productive, of truth.

But the measure of all truth is the reason of God, which is the first truth and productive of every other truth.

Therefore human reason is a true rule according as it is conformed to the reason of God (q. 19, a. 4).

2. In human acts good and evil are said according to the order to the ultimate end. But the ultimate end is constituted and intended by the author of nature. Therefore the supreme ordering of human acts is from God; and acts are good or bad according to the ordering of God.

3. Hence was condemned the proposition of the Syllabus, 3°: « Human reason, without any respect at all for God, is the sole arbiter of true and false, good and evil ».

They object: We do not know the eternal law; therefore it is not a rule. — R. It is made known through creatures and especially through the knowledge of human nature, for all things have from the eternal law that they are ordered and moved toward their end and toward the end of the whole universe: « Although the eternal law is unknown to us according as it

126. Corollary. — Human reason is the secondary and nearer proper or homogeneous and immanent rule; the eternal law the primary and supreme, heterogeneous, and transcendent rule (q. 19, a. 4, ad 2 ; q. 21, a. 1 ; q. 71, a. 6).