PART FOUR

ERRORS
TO WHICH HUMAN KNOWLEDGE
IS SUBJECT

CHAPTER 4

Reflective persuasion of truth and error

1335. After discussing the natural, spontaneous persuasion of the first principles (cf. 1143 ss.), I think it will be helpful to say something about the willed, reflective persuasion we form when we consent to truth or error. This is 'persuasion' in the exact sense of the word.

1336. What we have said so far shows that the reflective persuasion which human beings acquire about an opinion is the joint effect of will and reason.

'Such persuasion is the understanding's final rest in an assent given by the will to a proposition.'

The will moves and as it were envelops the understanding, which adheres to and comes to rest in a proposition. It is here that this kind of persuasion arises.

1337. When the proposition is formally false, the persuasion is more an act of the will than of the understanding. The will desires the proposition and, profiting from whatever confusion remains in the ideas, forces the understanding to a belief whose falsehood is not clearly seen by the understanding. In place of truth, the understanding easily believes and approves the confused falsehood. It will be helpful therefore if we recall the different levels at which the will's action produces persuasion in various cases of assent.

1338. Our apprehension of, and assent to the first principles is necessary, not free.
The apprehension is natural because carried out in us by nature itself. The assent which we irresistibly give the first principles is determined by their evidence.

1339. Evidence has its origin in the universality and necessity of the idea of being, in which the first principles are rooted. A thing can only be in the mode conveyed by this idea, which encompasses every possibility within itself and indeed is possibility. Our mind is necessitated to form all its true and false judgments according to this perfectly simple idea (the supreme rule of logic). False judgments however do not depend on this infallible rule but on the wrong use that the subject makes of it.

1340. The word 'evidence' deserves further explanation. It has been much abused by the different meanings given it. Its etymology, which expresses clear vision or perception, has been partly responsible for this abuse and for the uncertainty of philosophers about its meaning. Simple vision or perception is only a contingent fact, and we do not see how that which is contingent and accidental requires a necessary consent. Indeed, there have always been philosophers who posited erroneous and truthful evidence, and believed that they should enquire about the criterion of evidence.

In fact, the clear vision of anything does not generally speaking include a judgment. And there is a substantial difference between the vision and the thing seen. When our judgment about the thing seen is based solely on our vision of it, deception is possible: the vision, although distinct and clear, could be erroneous, that is, apt to make us believe the thing to be different from what it is.

To avoid these equivocations which change intellective evidence into a simple vision similar to that of external sight, we must explain the nature of intellective evidence and show that it includes the concept both of a clear and of a necessary apprehension of some thing. I define intellective evidence as follows: 'Intellective evidence is the apprehension of the necessity of a proposition.'
Understood in this way, intellective evidence presents not only the fact of perception but also the reason which irresistibly causes our assent and determines our judgment. This reason, having within itself intellective evidence, is the necessity of the proposition to which we assent.

1341. On the part of the understanding, the persuasion of intellective evidence is greatest in the first principles and eludes the forces of human freedom, which, as we have said, is unable to oppose nature or deny what the understanding necessarily sees.

1342. Intellective evidence is always a necessity seen by the understanding in a proposition (cf. 1338 ss.). The necessity of first propositions is of such a kind that it must be felt. But a number of consequential propositions do not manifest any necessity. Is there any intellective evidence for these propositions? The question can be answered only be examining the nature of the evidence of consequential propositions. 'The intellective evidence of consequential propositions is present when the propositions are seen in the principles'. This means that we clearly see the connection of a consequential proposition with the supreme principle, and that if the proposition were false, the supreme principle would also be false, which is impossible to be thought.

1343. A consequential proposition can be contained in the supreme, per se evident principle in two ways: 1. by its very nature, or 2. because of some fact or contingent condition. In the first case the proposition has an apodictic necessity and therefore apodictic evidence. In the second, the proposition has a hypothetical necessity and therefore hypothetical evidence. We can illustrate this by two examples.

The proposition, 'At this moment I must be moving or standing still', is said to be a necessary proposition; 'I am moving' is said to be a contingent proposition because the contrary is possible.

The propositions are correctly named provided they are considered abstractly as possible propositions. But if they are considered actually in a subject who has assented to both of them, the certainty which the subject has of both propositions equally contains some necessity. In the case of the first proposition, the necessity is apodictic; in the case of the second, hypothetical. Both propositions, joined to the reasonable assent given them, become necessary, but the first apodictically, the second hypothetically.

What I am saying can be better understood if the assent given to the necessity of the two propositions is expressed at the time they are made. In which case they become:

'I am certain that at this moment I must be moving or standing still,' and
'I am certain that I am moving.'

1344. The origin of the certainty expressed in the two propositions is simply a necessity.
The necessity of the assent given to the first proposition is the absolute necessity of the proposition. We see that it is impossible to think something different from that which the proposition states because there are only two possible opposite cases, movement or rest. The proposition includes all possibilities, and therefore constitutes apodictic necessity; it is an example of the principle of knowledge.

The necessity of the assent given to the second proposition does not originate in the proposition itself, which has nothing necessary within it. It arises from an implicit fact, that is, from the awareness I have of my movement and from the direct, natural perception which my understanding has of what is happening in my consciousness.(233) Granted the fact of the intellective perception of the movement, the movement is undeniable, because it is an element of the fact itself (cf. 1158 ss.). If my movement, at the time I perceive it intellectively, could not be, it would simultaneously be and not be. By means of the fact of perception, the per se contingent proposition becomes necessary; this is a particular instance of the principle of contradiction.
We can conclude, therefore, 1. that apodictic certainty is present when the necessity of the proposition, which constitutes its evidence, derives solely from the form of truth or the first principles without need of anything else; and 2. that hypothetical certainty derives from the first principles applied to a contingent fact of consciousness.

1345. Persuasion of deduced propositions is strong when they are seen in the principles. In this case, persuasion is produced more by the understanding than the will. But if the deduction is drawn out and the certainty depends on many contingent facts, the will has scope to make the understanding suspend its assent, and by confusing its ideas, disturb it in its vision.

1346. We need to describe carefully the state of our mind when it possesses truth through the first criterion of certainty, and actually sees truth. The description of this state is ultimately the criterion by which we are certain and, after reflection on our certainty, know we are certain, and can repeatedly tell ourselves so. The result is greater interior confirmation and satisfaction which completes our persuasion of truth and makes it unmovable.

1347. People who have not drawn a careful distinction between direct(234) and reflective knowledge, but confined their attention to the latter, have discussed only a partial criterion of certainty. Instead of the true, universal criterion, they offer a partial criterion of reflective certainty, that is, they describe a state of the mind already in possession of certainty. They do not consider that a mind in possession of certainty must have already made use of some criterion. Hence the description of a state of mind in possession of certainty can constitute a criterion valid only for reflection. Such a criterion allows us to be aware of our previous possession of certainty and to confirm it.

1348. These thinkers, in order to describe this state of the mind, were content to have recourse to evidence as the criterion of certainty. But the various meanings of the word 'evidence' gave rise to many disputes which could be settled only by determining the characteristic of intellective evidence and thus avoiding confusion between the evidence of the senses and the evidence of the understanding. Such confusion is still present today in the miserably limited systems of materialists and sensists.

This is not the case among the greatest of the scholastics such as St. Thomas and the author of the Itinerary, where we do not find any confusion about the state of the mind in possession of certainty. For them the characteristic of intellective evidence is the necessity of any thing, that is, the intuition of the impossibility of its contrary. They located this state in the mind's clear vision that what is thought IMPOSSIBILE EST ALITER SE HABERE [CANNOT POSSIBLY BE OTHERWISE THAN AS THOUGHT].(235)
Now, having described in this way the state of the mind in possession of certainty through use of the first criterion, we have arrived at that final link and proposition for which we cannot justifiably seek another reason or criterion.(236)

1349. Certainty acquired by an extrinsic criterion consists in the knowledge of a secure sign of a proposition (authority, for example), but not in the vision of the final reason or of the necessity of the proposition.
The action of the will is more present in the assent which produces persuasion of this kind of certainty than in the assent which is given to the vision of an intrinsic necessity in a proposition.

1350. Nevertheless when the sign and its connection with the proposition that it indicates are both certain, necessity is present inducing the understanding to assent. The will however can easily remove the evidence provided by the sign and the connection, and so produce confusion of ideas. In this state the understanding can be enveloped by the will and easily suspend or even deny its adhesion and assent.
If persuasion is founded on an infallible authority, certainty can be stronger, relative to the persuasion and adhesion by the will, than the certainty of the first principles. But not relative to the understanding, which is more necessitated by the vision of the first principles than by authority, even infallible authority.(237)

1351. Because the first principles are contained in the supreme criterion itself of certainty, they have an intellective evidence or intrinsic necessity which compels the reason of every individual, in whom it induces an inescapable persuasion. But can these first principles be proved by the extrinsic, second criterion - in other words, in addition to the intrinsic necessity which makes the first principles intellectively evident, is there a secure sign which contradistinguishes them and enables them to be known separately?

At first glance the question appears absurd. We have said that a secure sign cannot exist unless the first principles have already been used to recognise it as such. However, on closer examination, the question is not entirely meaningless if we keep in mind the distinction between direct and reflective knowledge. Reflection alone is subject to disturbance and confusion, and consequently provides a home for error. Through reflection we can deny what we know directly. Sceptics do this when they deny the first principles with an operation appertaining to reflection, although it is impossible for them to lack direct knowledge of, or even avoid using, the same principles to deny their very existence; in fact they have to use them in whatever they think.

But the first principles, necessarily granted by each individual human being, are therefore granted by all. This universal, human consent forms common sense, which is a sign of the principles. For this reason I said that common sense is an excellent rule for those whose mind has become so confused, and their reflection so disturbed, that they believe they doubt the principles. This rule is however a particular case of the extrinsic, secondary criterion of certainty. It is valid for the certainty of the first principles relative to reflective knowledge but not for their certainty in general. The rule can confirm and certify the reflective knowledge of the first principles, and by means of reflection discern these principles from all others.

1352. We need to note carefully that the consent of the human race can be called common sense only when it is produced by the truth. Although a first truth essential to human beings must undoubtedly produce the effect of common consent in mankind, a similar effect can sometimes be produced without intrinsic contradiction by an error, because both the individual human being and the masses are fallible. Even if this were not granted in fact, it is still not intrinsically contradictory to human nature.(238)
How, then, do we say that the general consent of human beings can discern the first principles for someone who has erred? And how therefore can this consent be called a criterion suitable for use as a guide for reflection? I answer as follows.

1353. Even though our reflection is disturbed and confused, the first principles are always seen clearly with direct knowledge; they are never extinguished in us. I maintain that this light, which always lives in us in the first principles, can be made visible and brought before the distracted gaze of sceptics by the authority of others. The criterion of reflection for the first principles is not constituted by human authority alone but by the inextinguishable light of the principles aided and strengthened by human authority, which of itself could not certify anything; better, our vision is corrected to see the principles.

By the aid of the light remaining in us, therefore, we use the authority of the human race to confirm the first principles. We are thus able to restrict this authority, which tells us so many things, true and false, and proffers so many principles and consequences. We can, if we wish, discern among all the different cases those in which human authority pays suffrage to the first principles, and determine these alone as principles which, in addition to being approved by the human race, find in our mind a harmonious correspondence, a witness that serves as an interpreter of authority, just as authority in its turn interprets and enlightens that internal witness.

The authority of the human race therefore does not by itself form the criterion of the reflection we are discussing. Human authority and what we may call the remnant of reason left in fallen human nature, to which authority comes as a support, form a single criterion and rule of the truth.

1354. Persuasion about error is possible but it refers more to the action of the will than to that of the understanding. This is the opposite of what we have said about the different kinds of persuasions dealt with so far; these spring from the truth of something, truth known with either the intrinsic or extrinsic principle of certainty.

1355. In producing persuasion, truth has within itself a force to determine the understanding. But when we persuade ourselves of what is false, we persuade ourselves of something which has no power to determine our understanding; it has no existence, because what is false does not exist. Truth exists of itself, and in direct knowledge, but what is false is found neither expressly nor virtually in direct knowledge.

What is false therefore is always fabricated knowledge, as I have said. And a fabrication is something created by the will, which moves the confused intellect. The intellect gives in to the will's movement, decides that what is false is true, and forms an idol from it. Like all fabrications, this false matter, determined by the understanding, is a purely mental entity. The action producing it appertains to the faculty of word, that is, of the judgment. Errors can therefore fittingly be called false words or interior lies.

1356. Mental entities, created by the mind, are not per se false, but become so 1. when we consider them as existing in themselves and not as mental; 2. when we take them as mental but judge they have a foundation in direct knowledge, which they do not have.

1357. Furthermore a mental entity always manifests the limitation of the human mind. This is the limitation of mental conception which, as a process, corresponds poorly to the nature of the thing conceived. Because of this, antiquity recognised a subjective element in cognitions, although it also noted that such an element does not necessarily deceive us or render our cognitions false. Our understanding, which is universal, allows us to know that this element is subjective without our being constrained to take it as objective, the only way in which it would be false.(239)

1358. Error therefore can arise in two ways:
Either 1. an entity is formed by the understanding which, contrary to fact, declares that the entity is indeed in the mind, as in the following proposition: 'An effect exists without any cause.' In this kind of error the ideal, mental entity is lacking.

Or 2. a mental entity is formed and declared to be something real and extrinsic, for example, 'Maurice is alive', when in reality he is dead. In this kind of error the extrinsic entity or reality is lacking.

Error is therefore an effort of the understanding to see an entity where no entity exists, or to see an entity different from that which exists. In such an action the term of understanding is a void, nothingness.(240)

1359. This explains why persuasion about error is fabricated. Error is entirely the action of the human being, a blow against nature, an attempt of the will to seduce the understanding which per se is attracted and determined only by the light of truth.
Hence, because direct knowledge is always true and indestructible, persuasion about error lies solely in reflection, which is an action added as it were to human nature. Truth, the foundation of our mind, precedes reflection and is always present, able to be seen. Those who err are never, perhaps, totally unmindful of it.

1360. Error is always superficial and never penetrates deep into human nature. Persuasion about error, no matter how well entrenched, is often full of uncertainties and doubts which, although apparently solved, continue to reappear. A mysterious unrest never really abandons those in the grip of error, although it has no strength in itself to turn them back to the peace of truth.

1361. An erroneous understanding terminates not in truth but in a fabricated object void of all entity (cf. 1354 ss.). As I said, the term of an erroneous understanding is per se nothingness. An erroneous understanding is without knowledge and does not acquire knowledge. Contrary to the understanding's belief, its term has no entity - the understanding says it sees, but in fact sees nothing and therefore lies to itself. Such is the empty knowledge of those in error.

1362. Error is always ignorance. However, while one kind of ignorance is a simple negation of knowledge, error adds to this negation the force of understanding moved by the will. The aim is to fabricate an empty being in place of absent knowledge, and thus allow ourselves to imagine that we know. But not knowing, and telling ourselves we do know, is a hidden lie of pride. Every formal error therefore is a secret act of pride; every error is essentially pride.(241)
Antiquity, in order to differentiate this negation of knowledge from simple ignorance, called it appropriately 'privation'.

(233) Hence antiquity said that intellective knowledge always concerns that which is necessary. Intellectus, says Aristotle, et sapientia et scientia non sunt contingentium sed necessarium [Understanding, wisdom and knowledge concern necessary, not contingent things] (Eth., bk. 6, c. 6). St. Thomas says that the things treated by the branches of knowledge are sometimes contingent, but are not the sciences themselves, that is, not the universal reasons used for considering contingent things: Nihil enim est adeo contingens, quin in se aliquid necessarium habeat. Sicut hoc ipsum quod est Sortem currere, in se quidem contingens est, sed habitudo cursus ad motum est necessaria. Necessarium enim est Sortem moveri, si currit [Nothing is so contingent that it does not have in itself something necessary. The fact, for example, that Socrates is running is in itself contingent, but the ability to run is necessary for motion. It is necessary for Socrates to move if he runs]. He shows that the necessary element in contingent things comes from the intellect, which always considers them in relationship to its universal concepts (S.T., I. q. 86, art. 3).

(234) Any knowledge whatsoever (even that which per se is reflective) can be called relatively direct when it is considered relative to another reflection upon it.

(235) The following is the whole passage in the Itinerary where the author describes the state of the mind in possession of intellectual evidence through the first criterion: Tunc intellectus noster dicitur veraciter comprehendere (propositiones) cum certitudinaliter scit illas veras esse: et hoc scire est scire: QUONIAM NON POTEST FALLI IN ILLA COMPREHENSIONE, scit enim quod veritas illa NON POTEST ALITER SE HABERE. Scit igitur veritatem illam esse incommutabilem [The human intellect is truly said to comprehend (propositions) when it knows with certainty that they are true. To know this is to know THAT THE INTELLECT CANNOT ERR IN THE COMPREHENSION. IT KNOWS THAT THE TRUTH CANNOT BE OTHERWISE, that the truth is unchangeable] (Itin. mentis etc., 3). St. Thomas makes necessity the characteristic note of intellective evidence when he writes: scire est causam rei cognoscere, et quoniam IMPOSSIBILE EST ALITER SE HABERE [To know is to know the cause of a thing, that is, to know that IT CANNOT POSSIBLY BE OTHERWISE] (De Verit., q. 10, art. 10).

(236) Anyone looking for the criterion of intellective evidence would be looking for the impossible, because the criterion would either have, or not have intellective evidence. If it did not have intellective evidence, it would be valueless. If it had such evidence, we would have returned to the first criterion, idem per idem. Thus the Schools very aptly said in this regard: Ratio non est quaerenda eorum quorum non est ratio [A reason must not be sought for things which have no reason] (Jn. Duns, Quodl., q. 16).

(237) Assent is produced by two causes: 1. the force of the motive determining the understanding; and 2. the force of the will. The will acts more noticeably than the understanding in producing Christian faith. And its action also acquires the nature of virtue precisely because it is an action of the will. On the other hand, the assent of the understanding is determined more directly by the first principles than by infallible authority. To understand how reliable these distinctions are, we must note the difference between certainty and truth. There are indeed no degrees in truth because truth is simple and immutable. But certainty is truth perceived by us, that is, it is 'a firm, reasonable persuasion that conforms to the truth'. Degrees of greater intension and firmness can therefore be assigned to our perception of, and adhesion to truth, in other words, to our persuasion. We cannot therefore assign degrees in certainty relative to truth, but relative only to the act of our powers. This teaching is held by the two perceptive Italians whom we have quoted many times. One of them, St. Bonaventure, compares the certainty of faith with the certainty of reason as follows: DE CERTITUDINE ADHAESIONIS (which means relative to the will) verum est fidem esse certiorem scientia philosophica. Si autem loquamur de CERTITUDINE SPECULATIONIS, quae quidem respicit ipsum intellectum (and therefore not the will) et nudam veritatem, sic concedi potest quod maior est certitudo in aliqua scientia ita certitudinaliter nosse quod nullo modo discredere, nec in corde suo ullo modo contradicere potest, sicut patet in cognitione dignitatum et primorum principiorum ['RELATIVE TO THE CERTAINTY OF ADHESION' (which means relative to the will) 'it is true that faith is more certain than philosophical knowledge. But if we are talking about the CERTAINTY OF SPECULATION, which concerns the intellect' (and therefore not the will) 'and pure truth, it can be granted that certainty in some branches of knowledge is greater than in faith, simply because by means of knowledge someone can know something with certainty which he cannot in any way disbelieve, or contradict in his heart, as is clear in the knowledge of values and the first principles'] (In 3 Sent., D. 23, art. 1, q. 4). We see the same teaching in St. Thomas' De Veritate, q. 10, art. 2.

(238) The case does not in fact take place because the light of revelation has prevented it, not because humanity has the essential power to avoid it. But the following case is found: 'A human being can find the same error present in all those people with whom he speaks and can speak during his whole life.' Thus there is no way in which he can know of the existence of other human beings who hold a different opinion, or that other times will come when a different opinion is held. For many slaves in the ancient world and for many in the hands of unbelievers in modern times, it was and still is impossible to find in the authority of one's fellows the means of ridding oneself of many errors.

(239) St. Thomas distinguishes 1. the act or mode of understanding, which appertains to the subject and is conformed to the subject; and 2. the object of understanding, which is independent of the subject. For example, we understand material things with a simple, immaterial act, but we do not attribute simplicity and immateriality to the thing understood. On the other hand, we understand God with multiple acts, but do not attribute multiplicity to God. Our understanding, by means of its universality, is able to distinguish what we, the subject, add to our way of understanding, and what belongs to the thing. The known thing therefore is not altered by the knowing subject; it is not rendered subjective. Only the mode or act of understanding remains subjective. This brilliant distinction is sufficient to destroy critical scepticism. We see that critical philosophy is founded solely on a confusion of ideas. It has intermingled the mode or act of understanding with the object understood - two things which our predecessors had so carefully distinguished.

(240) I have distinguished three kinds of persuasion: 1. Persuasion dependent upon the first criterion, which shows a truth intrinsic to the proposition to which we assent. The understanding plays a large role in this kind of persuasion. 2. Persuasion coming from the second criterion, which shows that the proposition assented to is true, but that we know the truth through a secure sign, for example, infallible authority, and not as intrinsic to the proposition. The understanding is less involved here than in the first case; the will is more involved. 3. Persuasion coming from error. Here the principal action is that of the will; the understanding with a function of its own obeys the will, not vice versa. St. Augustine deals with these three kinds of persuasion in his little work, De utilitate credendi. He calls them understanding, believing, and guessing.

(241) St. Augustine, who discerned the secrets of the human heart so well, made the same observation: 'To guess' (which for Augustine means the same as to err) 'is reprehensible for two reasons: first, the person persuaded that he knows' (that is, someone in error) 'is unable to learn even that which he could otherwise learn, and second, temerity is in itself a sign that the desires in the spirit are not as they should be. - Therefore the credulity of those who guess that they know what they do not know is defective' (De util. cred., 11). St. Thomas himself calls this presumption mater erroris [the mother of error] (C.G., I, 5). Consequently, the accusation of credulity can be levelled only at those who err. Those who presume they believe nothing are in no way free from the defect of credulity: they are credulous of error, and in this alone, according to the great men we have quoted, defective credulity properly speaking consists.