Thomas Aquinas, Disputed Questions on Truth (De Veritate)

1. After discussing synderesis, Jerome remarks: "We sometimes see this fall down." But, in matters of action, to fall down is nothing else than error. Therefore, synderesis can err.

2. Although error, properly speaking, belongs not to a habit or a power, but to the man, since acts belong to individuals, a habit or a power is said to err in so far as through the act of some habit or power a man is led into error. But a man is sometimes led into error through the act of synderesis. For in the Gospel of St. John (16:2) it is said: "Yea, the hour cometh, when whosoever killeth you, will think that he doth a service to God." Thus, from the judgment that worship must be offered to God, which judgment certainly pertains to synderesis, some were disposed to kill the Apostles. Therefore, synderesis errs.

3. Jeremias (2:16) says: "The children, also, of Memphis, and of Taphnes have deflowered thee, even to the crown of thy head." But the crown is the higher part of the soul, as the Gloss on Psalms (7:17) says: "His iniquity shall come down on his crown." Thus, it belongs to synderesis, which is the highest thing in the soul. Therefore, synderesis is deflowered through sin by demons.

4. According to the Philosopher the power of reason is related to opposites. But synderesis is a power of reason. Therefore, it is related to opposites, and so can do good and commit sin.

5. Opposites are naturally produced in connection with the same thing. But virtue and sin are opposed to each other. Since, therefore, the act of virtue is in synderesis, because it urges on to good, the act of sin will also be in it.

6. Synderesis takes the place in matters of action which the understanding of principles does in speculative matters. But all the activity of our reason arises from first principles. Therefore, all the activity of practical reason has its beginning from synderesis. Therefore, just as the activity of practical reason which is virtuous is ascribed to synderesis, so the activity of reason which is sinful is also attributed to it.

7. The punishment corresponds to the crime. But the whole soul of the damned, including synderesis, will be punished. Therefore, synderesis also sins.

To the Contrary:

1'. Good can be more pure than evil, for there is some good in which there is no admixture of evil, but there is nothing so bad that it does not have some admixture of good. But in us there is something which always inclines to evil, namely, the tendency to sin [fomes]. Therefore, there will be something which always inclines to good. But this seems to be only synderesis. Therefore, synderesis never sins.

2'. What is naturally present is always present. But it is natural for synderesis to warn against evil. Therefore, it never consents to evil, and so never sins.

REPLY:

In all its activities nature intends what is good and the conservation of the things which are produced through the activity of nature. Therefore, in all the works of nature, the principles are always permanent and unchangeable and preservative of right order. For, as is said in the Physics: "Principles should be permanent." For it would not be possible to have any stability or certainty in things which flow from principles if the principles themselves were not firmly established.

Consequently, all changeable things are reduced to some first unchangeable thing. Hence, too, it is that all speculative knowledge is derived from some most certain knowledge concerning which there can be no error. This is the knowledge of the first general principles, in reference to which everything else which is known is examined and by reason of which every truth is approved and every falsehood rejected. If any error could take place in these, there would be no certainty in the whole of the knowledge which follows.

As a result, for probity to be possible in human actions, there must be some permanent principle which has unwavering integrity, in reference to which all human works are examined, so that that permanent principle will resist all evil and assent to all good. This is synderesis, whose task it is to warn against evil and incline to good. Therefore, we agree that there can be no error in it.

Answers to Difficulties:

1. Synderesis never falls down in a general principle, but error can happen in some application of a general principle to some particular case because of a false deduction, or because of a false assumption. Therefore, it does not say that synderesis simply falls headlong, but that conscience does, which applies the general judgment of synderesis to particular matters.

2. When in a syllogism one arrives at a false conclusion from two propositions, one of which is true and the other false, the mistaken conclusion is not attributed to the true, but to the false, proposition. Therefore, in that choice by which the murderers of the Apostles thought they were offering worship to God, the error did not come from the universal judgment of synderesis, that worship should be offered to God, but from the false judgment of higher reason, which considered the killing of the Apostles as pleasing to God. Therefore, we need not concede that they were inclined to sin through an act of synderesis.

3. As the crown of the body is the highest part of the body, so the crown of the soul is the highest part of the soul. Hence, the crown of the soul is understood to mean different things according to the different distinctions of the parts of the soul. If we distinguish the intellectual part from the sensitive part, the whole intellective part of the soul can be called the crown. If we distinguish the intellective part further into higher and lower reason, higher reason is called the crown. If we distinguish reason further into natural judgment and deliberation of reason, natural judgment is called the crown. Therefore, when the soul is said to be deflowered even to its crown, crown is to be taken as denoting higher reason and not synderesis.

4. The power of reason, which of itself is related to opposites, is sometimes limited to one thing through a habit, especially if the habit is completely formed. Moreover, synderesis does not mean the rational power simply, but as perfected by a completely determined habit.

5. The act of synderesis is not strictly an act of virtue, but a kind of prelude to the act of virtue, just as natural endowments are preludes to freely given and acquired virtues.

6. Just as in speculative matters, although a mistaken reason starts from principles, it does not derive its falsity from first principles, but from wrong use of the principles, so the same thing also happens in practical matters. Therefore, the conclusion does not follow.

7. Augustine shows that this argument does not hold. For he says that "the whole man is damned" for the sin of lower reason alone, and this because both reasons belong to the "one person," to whom sinning properly belongs. Therefore, the punishment looks directly to the person and not the power, except in so far as the power belongs to the person. For the person of man deserves punishment in all the parts of his person for a sin which he commits by one part of himself. Hence, also, in a civil trial the hand alone is not punished for the murder which a man commits with his hand.