7.1 Aquinas on Knowledge
The verb “to know” occurs in sentences in which it surely does not mean exactly the same thing. Consider, for example, “I know that someone is ringing my doorbell,” “I know that Paris is the capital of France,” “I know that most people die before they reach the age of 100,” “I know that it was once fashionable for Englishmen to wear spats,” “I know that there are three letters in the word ‘cat,’ ” “I know what a cat is,” and “I know that ‘God’ translates the Latin ‘Deus’ into English.” What is going on with me as I “know” all these things seems to be varied. To know that someone is ringing my doorbell is just to register the fact that my doorbell is ringing, and not of its own accord. Knowing that Paris is the capital of France is to grasp something precise concerning something particular. Again, knowing something about “most people” is to be aware of a generalization, not a fact about anyone in particular, as is knowing that spats were once fashionable in certain circles. And, while knowing that “cat” contains three letters is knowing something about a word, knowing what a cat is presumably involves knowing what it takes for a cat to exist at all, while knowing that the word “Deus” can be translated as “God” is to have some ability to read both Latin and English.
So “knowledge” does not always signify exactly the same thing, and Aquinas is aware of this fact. He does, however, think that knowledge always involves a cognition or awareness of some kind, an assimilation of what can be flagged by a possibly true proposition, even if the proposition is actually false.1 When it comes to people, whom Aquinas takes to be the highest and best understood knowers of our acquaintance, knowledge is always the result of an intellectual contact with material things.
When I sit on a chair, the chair and my backside make contact, but not intellectually. What, though, if I observe a chair and am able to talk about it? Then I and the chair seem to come together as two contiguous physical things do not.
Again, what if my cat looks at a book the pages of which I present to it so that it can rub its nose into them? Again, there is contact. But is it intellectual?
Aquinas thinks that when it comes to people there is more than mere physical contact involved in the coming about of knowledge, however varied the objects of knowledge are, however different might be what we put after the word “that” in sentences like “I know/believe/recognize that ___.”
According to Aquinas, knowledge is what things with intellect (intellectus) possess or can possess. Aquinas would agree that, for instance, my cat can be said to know that I am its source of food, though my cat lacks intellect. But he would have taken this “knowledge” on the part of my cat to be nothing but a reaction to me based on previous experience and its nature as a food-seeking feline: instinct married to habituation, not understanding or cognition in a more developed sense, not what Aquinas refers to as intellectus and ascribes to people when using the verbs intelligere, scire, and cognoscere, all of which can be translated as “to know.”
Things with intellectus, says Aquinas, can have scientia or cognitio, both of which terms can be translated by “knowledge.” Aquinas thinks of scientia, which he views as a kind of cognition, as knowledge in the fullest or highest sense, for he takes us to have scientia when we thoroughly understand what something is by nature, what its essence amounts to (see chapter 2, section 1 here). For Aquinas, to have scientia is to have followed a demonstration through to its necessary conclusion. It also involves grasping the truth of the premises that entail such a conclusion. But cognitio is also important for Aquinas since he thinks of it as at work when we take in the world around us by sensation and as we frame, or even entertain or accept, propositions that we understand, even if they do not amount to what we have demonstrated, or even if they do not amount to what Aquinas would have considered to be universal truths or real definitions of actually existing things.
Sometimes Aquinas speaks of knowledge occurring as we “receive” the forms of material things “immaterially.” This may strike you as an odd or even unintelligible idea, but Aquinas takes it to be obviously right. Material things, he says, have forms in that they are things of a certain natural kind or in that they have accidents that really inhere in them. So, thinks Aquinas, my cat is a cat since being a cat is what it is by nature, and my cat is black and white since its coat is black and white. Aquinas takes this to mean that my cat has a certain substantial form (what it takes for it to exist as a cat) and various accidental forms (features that it happens to have but could lose without ceasing to be a cat). For Aquinas, my cat’s substantial and accidental forms are real and ascribable to my cat, which has them just by being what it is substantially or accidentally. But what must be going on if I understand what a cat is? Then, says Aquinas, what exists in a cat substantially or accidentally must somehow exist in me even though I am not a cat.
The thought here is that in knowing what something is there has to be an intellectual taking in of what the thing actually is. There has, in the knower, to be something of what the thing known is. If there is not, thinks Aquinas, then the knower and thing known will not truly relate to each other or make contact with each other as knower and known. Aquinas is clear that things can be related to each other in different ways. He thinks that people can be related to each other by virtue of their respective physical positions or by virtue of the fact that one person is having some kind of effect on another one. Again, he would agree that X can be thought of as related to Y because X has some kind of sensory contact with Y, as, for example, my cat does with me as it lies on my lap. For Aquinas, however, knowing what something is cannot be equivalent to physical relation or sensory relation since it amounts to intellectually grasping what the thing truly is in itself, while there need be no such grasping when two things are physically related to each other or when one thing senses another. So, Aquinas concludes, I know what a cat is by having what it takes to be a particular cat formally without myself being an actual cat, and he takes this to mean that what exists in a cat materially comes to be in me without belonging to a material cat. Aquinas holds that one can only know what is intelligible and that physical things are potentially intelligible insofar as what they are can be understood. But the coming to be understood of potentially intelligible physical things, he says, can only occur as what exists in them formally comes to be in the intellect of a knower as form without matter.
We can distinguish between the questions “What does it mean to be a cat?” and “What does the word ‘cat’ mean?” What it means to be a cat is to exist as whatever a cat is. Yet understanding what “cat” means cannot be that. Understanding what a cat is has to be different from being a cat, even though it must involve the intelligible factor in cats coming to exist in one, and Aquinas would say the same when it comes to understanding what anything at all is. For him, anything potentially intelligible comes to be understood as it exists in knowers as understood, as what is potentially intelligible comes to be without being confined to matter. Hence his idea of knowledge occurring as we receive or are informed by the forms of material things immaterially. For Aquinas, knowledge or intellect is had by something only insofar as its way of being includes existence unrestricted by matter, insofar as it has received various forms without matter.2