Ordinatio

As to the second article [n.218], so that the error of the academics have no place in any knowables, one needs to see how one should speak about the three aforesaid knowables [nn.224-228] – namely about principles known per se and conclusions, and second about things known through experience, and third about our own acts – whether it be possible for infallible certitude of them to be had.

[About the knowledge of principles and conclusions] – As to certitude about principles, then, I say as follows: the terms of principles known per se have such an identity that the one evidently necessarily includes the other, and so the intellect, combining the terms from the fact it apprehends them, has in itself the necessary cause of the act of combining’s conformity with the very terms of which it is the combining, and has also the evident cause of such conformity; and so necessarily plain to it is the conformity whose evident cause it apprehends in the terms. Therefore, there cannot be in the intellect an apprehension of the terms and a combining of them without there being a conformity of the combining with the terms, just as a white thing and a white thing cannot be without there being a likeness between them. Now this conformity of the combining with the terms is the truth of the combining; therefore, the combining of such terms cannot be without being true, and so there cannot be perception of the combining and the perception of the terms cannot be without there being perception of the conformity of the combining with the terms, and so perception of the truth, because the first perceived things evidently include perception of this truth.

This reason is confirmed through a likeness, from the Philosopher Metaphysics 4.3.1005b29-32, where he maintains that the opposite of a first principle cannot arise in anyone’s intellect, namely the opposite of this principle ‘it is impossible for the same thing to be and not to be’, “because then contrary opinions would exist in the mind together;” which is of course true of contrary opinions, that is, of opinions formally repugnant, because an opinion opining ‘it is’ of something and an opinion opining ‘it is not’ of the same thing are formally repugnant.

So I will assert in the issue at hand some repugnance of understandings in the mind, though not formal repugnance. For if knowledge of whole and part stands in the intellect, and the combining together of them, then, since these include, as by necessary cause, the conformity of the combining with the terms, if the opinion stand in the intellect that this combining is false, cognitions will stand that are repugnant, not formally, but one cognition will stand with another and yet it will be the necessary cause of a cognition opposite to it, which is impossible. For just as it is impossible for white and black to stand together (because they are contraries formally), so is it impossible for white to stand together with what is precisely cause of black so necessarily that it cannot be without it without contradiction.

When certitude about first principles is had [nn.230-232], it is plain how it will be had about conclusions inferred from them, on account of the evidence of the form of a perfect syllogism; for the certitude of the conclusion only depends on the certitude of the principles and on the evidence of the inference.

But will not the intellect surely err in this knowledge of principles and conclusions, if all the senses be deceived about the terms? I reply that, as far as concerns this knowledge, the intellect does not have the senses as cause but only as occasion. For the intellect can have of simples only knowledge received from the senses, but, once the knowledge is received, it can by its own virtue combine the simples together. And if by reason of such simples the combination of them is evidently true, the intellect will by its own virtue and that of the terms assent to the combination – not by virtue of the senses from which it exteriorly takes the terms. An example: if the idea of ‘whole’ and the idea of ‘being greater’ is received from the senses, and if the intellect put together this proposition, ‘every whole is greater than its part’, the intellect will by its own virtue and by that of these terms assent indubitably to this combination, and not only because it saw the terms conjoined in the thing (the way it assents to this complex, ‘Socrates is white’, because it sees that these are united in the thing). Rather I say that if all the senses from which such terms are received were false, or if (and this counts more for deception) some senses were false and some were true, the intellect would not be deceived about such principles, because it would always have in itself the terms that were cause of the truth; as suppose that on someone born blind were miraculously impressed in a dream the species of white and black, and suppose these species remained afterwards when he was awake, the intellect by abstracting would combine from them this proposition, ‘white is not black’, and about it the intellect would not be deceived although the terms be received from erring sense; for the formal idea of the terms, which has been reached, is the necessary cause of the truth of this negative proposition.

[About knowledge through experience] – About the second knowables, namely things known through experience [n.229], I say that although experience not be had of all singulars but of many, and not always but often, yet someone with experience does infallibly know that it is so always and in all things, and this through this proposition residing in the soul, ‘whatever happens for the most part from a non-free cause is the natural effect of that cause’. This proposition is known to the intellect although it had taken its terms from erring sense, because a non-free cause cannot produce non-freely an effect for the most part, the opposite of which it is ordered to, or which it is not ordered to by its form. But a chance cause is ordered to producing the opposite of a chance effect or not to producing it; therefore nothing is a chance cause of an effect that is frequently produced by it, and so, if it not be free, it will be the natural cause.¹ And this effect comes about from the cause for the most part. This is taken from experience because by finding such a nature now with this sort of accident now with that, what is found is that, however much there were a diversity of accidents, always was such effect following this nature. Therefore, not from something accidental to this nature but from the nature itself in itself does such an effect follow.

But further must be noted that sometimes experience of a conclusion is received, as that the moon is frequently eclipsed, and then, with the conclusion supposed because it is so, a cause of such conclusion is looked for by way of division. And sometimes advance is made from experience of the conclusion to principles known from the terms, and then from such principle known from the terms can the conclusion, known previously only by experience, be known more certainly, namely with the first kind of knowledge, because known as deduced from a principle known per se [nn.229-230] – the way this is per se known, that ‘a dark body interposed between a perspicuous body and the light is preventing the multiplication of the light to such perspicuous body’. And if it has been found by division that the earth is such a body interposed between the sun and the moon, this will be known most certainly by a demonstration ‘because of which’ (because through the cause), and not only by experience, in the way this conclusion was known before the finding of the principle.

Now sometimes there is experience of a principle, so that it is not possible to find by way of division a further principle known from the terms, but a stand is made in something true for the most part, whose extreme terms are by experience known to be frequently united, for example that this herb of this sort of species is hot. And there is no other middle term found prior by which the property may be demonstrated ‘because of which’ of the subject, but a stand is made in this as something first known because of experience. Although then uncertainty and fallibility may be removed by this proposition, ‘an effect for the most part of a non-free cause is the natural effect of it’, yet this is the last degree of scientific knowledge. And perhaps there actual knowledge is not had of the union of the extreme terms, but aptitudinal knowledge. For if the property is an absolute thing other than the subject, it could be separated from the subject without contradiction, and the experienced person would not have knowledge because it is so, but because it is naturally apt to be so.

[About our acts] – About the third knowables, namely our own acts [n.229], I say that there is certitude about many of them just as there is of things known first and per se, which is plain from Metaphysics 4.6.1011a3-9, where the Philosopher says of the arguments of those who say that all appearances are true, that those arguments ask “whether we are now awake or sleeping; and all such doubts have the same force; for they make it an axiom that there is a reason for everything.” And he adds, “they are seeking a reason for things of which there is no reason, for there is no demonstration of a principle of demonstration.” So, for him there, ‘we are awake’ is known per se like a principle of demonstration; nor is it an objection that it is contingent because, as was said elsewhere [Ord. Prol. n.169], there is an order in contingent things, that some [contingent] is first and immediate, else there would be a process to infinity in contingent things, or some contingent would follow from a necessary cause, each of which is impossible.

And just as there is certitude about being awake as about something known per se, so also about many other acts that are in our power (as that ‘I understand’, ‘I am hearing’), and about others that are perfect acts. For although there is no certitude that I am seeing a white thing located outside, or in such a subject or at such a distance, because an illusion can happen in the medium or in the organ and in many other ways, yet there is certitude that I am seeing, even if an illusion happen in the organ. And this seems most of all an illusion, namely when an act of the sort that is of a nature to be brought about by an object present is brought about in the organ not by an object present. And so if the power had its own action when such a position is posited, truly would that be there which is called vision, whether it be an action or a passion or both. But if an illusion were to happen, not in the organ proper, but in something close to it which seems to be the organ – as if an illusion were not to come about in the bundle of nerves, but in the eye itself an impression were to come about of a species of the sort that is naturally brought about by a white thing – still vision would see, because such a species, or what is of a nature to be seen in it, would be seen. For it has distance enough as regard the organ of sight that is in the bundle of these nerves, as appears in Augustine On the Trinity 11.3 n.4, that the reliquies of things seen remaining in the eye are seen with the eyes closed; and in the Philosopher On Sense and Sensed Object 2.437a23-26, it appears that the fire [sc. the ‘flash’], which is generated from a violent upward raising of the eye and multiplied, is seen up to the shutting of the eyelid. These are true seeings, though not the most perfect, because here there is sufficient distance from the species to the principal organ of sight.

But how is certitude had of things that are subject to acts of sense, as that something outside is the sort of white or hot it appears? I reply: Either the same things about such an object appear opposite to diverse senses, or they do not, but all the senses that know it have the same judgment about it.

If in the second way, then certitude of the truth is had of this sort of thing known through the senses, and through this preceding proposition [n.235], that ‘what comes about for the most part from something, that something is the natural cause of it, provided it not be a free cause’. Therefore, when from this present something such a sort of change of the senses happens for the most part, it follows that the change, or the species generated, is the natural effect of such a cause; and so such external thing will be white or hot, or something else of the sort that is of a nature to be presented through the species that is for the most part generated by it.

Now if diverse senses have diverse judgments about some external seen thing – as that sight says a stick is broken part of which is in water and part in air, that sight always says the sun is of less size than it is, and that everything seen from a remote distance is smaller than it is – in such things there is certitude about what is true and which sense is erring through a proposition resting in the soul that is more certain than any judgment of the senses, and through the concurring acts of several senses; so that always some proposition sets the intellect right about the acts of the senses, which is true and which is false; and in this proposition the intellect does not depend on the senses as on a cause, but as on an occasion.

An example. The intellect has this proposition resting in it, ‘no harder thing that is broken by the touch of something soft yielding to it’. This is so per se known from the terms that, even if the terms were taken from the senses, the intellect cannot doubt of it; indeed, the opposite includes a contradiction. But that the stick is harder than water and that water yields to it, this each sense states, both sight and touch. It follows, therefore, that the stick is not broken as the senses judge it broken; and so the intellect judges which sense errs about the breaking of the stick and which does not through something more certain than any act of sense.

Similarly, on the other part [sc. the size of the sun, n.242], that a quantity applied to a quantity is altogether equal to it, this is known to the intellect however much the knowledge of the terms be taken from an erring sense; but that the same quantity could be applied to something seen near and far off, this do both sight and touch say; therefore a quantity seen near at hand or far off is equal; therefore the sight when saying it is smaller is in error.

This conclusion [n.244] is proved from principles known per se, and from the acts of two senses knowing for the most part that it is so. And so, whenever reason judges the senses to be erring, it judges this not through any knowledge precisely acquired from the senses as cause, but through some knowledge occasioned by the senses, in which it is not deceived even if all the senses be deceived [n.234], and by some other knowledge, acquired from a sense or senses ‘for the most part’, and these are known to be true by the proposition often cited [nn.235, 237, 241; n.228n], namely that ‘what is brought about for the most part etc.’²