Question 14 assumes that we share St Thomas’s view of Mind. St Thomas shows how what we know of Mind can also be said of God, and the ways in which God as uncaused cause must transcend what we understand of the operation of Mind.
This document takes what is said about our way of thinking, and abstracts it from the theology, so that we can approach Question 14 with a better understanding of St Thomas’s starting point, i.e. what he understands about intellect, and the human mind in particular. When we understand this, understanding the theology might be a bit easier.
Refer here to the guide to this question.
1.1 Characteristics of a “knowing” creature
The difference between a knowing and non-knowing creature (subject) is that the latter has nothing but its own form, whereas a knowing subject is one whose nature it is to have in addition the form of something else; for a species (representation) of the thing known is in the knower. Thus, the nature of a non-knowing subject is more confined and limited by comparison with knowing subjects. The latter have a greater scope and extension. As Aristotle says, ‘the soul is in a manner all things’.
Now form is limited by matter, so the freer forms are from matter the more they approach to a kind of infinity. So it is clear that something’s freedom from matter is the reason why it is able to know, and the capacity to know is in proportion to the degree of freedom from matter.
Thus we say plants have no knowledge because of their materiality. But the senses can know because they can receive the species of things without the matter. Intellect is still more capable of knowing because it is freer from matter and unmixed, as we read in Aristotle. So, since God is immaterial in the highest degree, it follows that he has knowledge in the highest degree.
Knowing is in the person who knows. It is a kind of living. Knowledge depends on the capacity of knowers; for what is known is in knowers according to the measure of their capacity.
Knowledge requires a likeness between the knower and the known.
Knowledge is of what is true.
Knowledge is a disposition. A disposition is intermediate between potentiality and actuality.
Knowledge is of conclusions, a kind of cognition caused by something else, namely from knowing principles.
The intelligible natures of things, as they exist in our knowledge are called ideas.
All knowledge is either universal or particular.
All knowledge comes about through a likeness.
In people different objects of knowledge imply different levels of knowledge
- In knowing principles we speak of ourselves as having understanding
- In knowing conclusions, science
- In knowing the highest cause, wisdom
- In knowing human actions, counsel or prudence
1.3 Relationship of Knowledge to what is Known
Whereas in activities which produce an external effect, the object of the activity (its end, or terminus) is something outside the agent, in activities which take place in an agent the object which is the end of the activity lies in the agent itself. The object in the agent is the activity actually taking place. Thus we find Aristotle saying that the actualisation of what is sensible is the senses while they are active, and the actualisation of what is intelligible is the intellect while it is active. We have actual sensation or actual knowledge because our intellect or senses are informed by the species of a sensible or intelligible object. Sense or intellect is different from the sensible or intelligible only to the extent that both are in a state of potentiality [with respect to the sensing (or understanding)].
We know something in two ways: in itself, or in another. We know something in itself when we know it through a species adequate to the thing itself, coterminous with the thing known, as when our eyes see someone through the species of that person. We see something in another when we see it through the species of what contains it, as when we see a part in a whole through the species of the whole, or as when we see someone in a mirror through the species of the mirror, and so of other ways in which we know one thing in another.
It is not the substance of something known that perfects a knower, but its species, by which it is in the intellect as a form and perfection. As Aristotle says, 'a stone is not in the soul; its species is'.
We do not specify understanding itself by what we understand in something else. We do so by the primary object understood, in which we understand other things. The proper object of understanding specifies understanding itself inasmuch as intelligible form is a source of understanding. For every activity is specified by the form which is the source of the activity, as heating is by heat. So, intellectual activity is specified by the intelligible form which makes the intellect to be actually knowing. And this form is the species of the principal object known.
Something is known for what it is only through its own proper idea.
To know things specifically is to know them, not merely in what they have in common, but in their differences from each other. For to know something generically and not specifically is to know it imperfectly. Hence our intellect, in passing from potentiality to actuality, attains first to a universal and confused knowledge of things, then to a knowledge of what is proper to each, thereby passing from incomplete to complete knowledge (as Aristotle makes clear in the Physics).
To know something “as it is in the knower” can be understood in two ways: (i) with “as” referring to the way the thing as known is in the knower. Taken thus it is false. For a knower does not always know something known as it exists in a knower. An eye, for example, does not know a stone as it exists in it. Rather, through the species of the stone that it has in itself, the eye knows the stone as it exists outside the eye. And if people do know the known object as it exists in knowers, they still know it as it exists outside knowers. So, the intellect, in knowing that it is knowing a stone, knows the stone in the intelligible existence it has in the intellect; but it still knows the existence which the stone has in its own nature, (ii) But if we take “as” to refer to a knower's manner of knowing, it is true that a knower knows the thing known only as it is in a knower; because the more perfectly something known is in a knower, the more perfect the degree of knowledge.
But according to Aristotle the condition of being able to call up knowledge covers many objects at the same time, while actual knowledge covers only one object.
Again, the knowable is prior to knowledge and is its measure, as we read in the Metaphysics
To understand is a kind of passivity and movement, as Aristotle states, and knowledge is an assimilation of the thing known. Also, something known is a perfecting of the knower. However, when we call the act of understanding a kind of movement or passivity, we use the expressions “to move” and “to be passive” equivocally, as Aristotle says. For the act of knowing is not a movement in the sense of an actualisation of something incompletely actualized and passing from one subject to another. It is the act of something completely actualized, taking place within the agent itself. Similarly, for an intellect to be perfected by what is intelligible, or assimilated to it, is proper to an intellect which is at some time in a state of potentiality. For in being potential itself, it differs from the intelligible, and is assimilated to it by the intelligible species which is the likeness of the thing known, and the intellect is completed by it as a potency that is actualized.
Understanding is an activity of some sort. But an activity is normally something proceeding from an agent. All understanding is the understanding of something. Understanding is a perfection and actuality in those who understand. As I have said, understanding is not an action that goes out to something external. It remains in an agent as its actuality and perfection (just as existing perfects things that exist). As form brings existence, so the intelligible species brings understanding. Understanding is not an activity going out from an agent. It remains in it.
Moreover, something understood perfects the one who understands.
1.5 Understanding understanding
Existence in nature does not belong to prime matter, which of itself is potential, except in so far as it is brought to actuality by a form. Now, our passive intellect has, in the order of knowing, the same condition as that of prime matter in the order of natural things. It is potentially able to receive intelligible forms as prime matter is potentially able to receive natural forms. So, our passive intellect can have an activity which it can know only when it is perfected by the intelligible species of something. In that way it knows itself through an intelligible species, as it does other things: for in knowing the intelligible it obviously knows its own act of knowing, and knows the power of knowing through the act of knowing.
Our intellect does not understand itself except as it understands other things (Aristotle)
“All knowers who know their own essence are in the condition of a complete returning”. [Book of Causes] For a thing to “return on its own essence” is simply for it to be self-subsistent. A form when it perfects matter by giving it existence, in a certain sense spreads itself out over the matter. But in so far as it has existence in itself, it returns on itself. So, those powers of knowing which are not subsistent but are the acts of certain organs, do not know themselves, as is clear in the case of each of the senses. But powers of knowing which are subsistent do know themselves. Hence the statement in the Book of Causes that “knowers who know their own essence return upon their own essence”.
1.6 Degrees of Knowing
Augustine says that “that which has comprehensive knowledge of itself is finite to itself” and “Everything that knows itself has comprehensive knowledge of itself.” We say that we comprehend (have comprehensive knowledge of) something when our knowledge of it can go no further, that is, when we know it as completely as it is knowable. For example, we comprehensively know a demonstrable proposition when we know it through demonstration, but not when we know it through some merely probable reason. But something is knowable in proportion to its actuality. As we read in the Metaphysics, something is known as actual, not as potential. Strictly speaking, “to comprehend” means “to hold or enclose some¬thing else”. Taken in that sense, all that is comprehended must be finite, as all that is enclosed must be. We may quote Augustine: “The whole is comprehended by vision when it is seen in such a way that no part of it escapes the one who sees.”
Understanding gets its specific content from an intelligible object, as every other act gets its specific content from its object. So, the excellence of understanding is in proportion to that of the object known.
But if something is known perfectly, its power must be known perfectly. Now the power of a thing cannot be known perfectly unless the objects to which the power extends are known.
Whoever knows a thing perfectly must know all that can happen to it.
1.7 Discursive Knowledge
To know an effect through a cause amounts to discursive knowledge. We know created effects in created causes, and thus pass discursively from causes to effects.
In our knowledge there is a twofold discursiveness:
- that of mere succession, as when after actually knowing one thing we turn to another thing;
- the discursiveness that involves causality, as when we come to know conclusions through principles.
Although understanding in itself is of something single, it is still possible to know many things in one thing, as I have said.
1.8 Knowledge as Cause
Knowledge either causes what is known or is caused by it.
The knowledge of artists is the cause of their products because they work through their intellects. So, the form in their intellects must be the principle of their activity, as heat is the principle of heating. But we may note that a natural form, merely as the form remaining in the thing to which it gives existence, does not indicate a principle of activity. It does so only in so far as it has an inclination towards producing an effect. Similarly, an intelligible form does not indicate a principle of activity merely as it is in the knower unless it is accompanied by an inclination, supplied by the will, towards producing an effect. An intelligible form is indifferent to opposite courses, since one and the same knowledge covers contraries. So, a form would not produce a determined effect if it were not determined to one course by desire, as we read in the Metaphysics.
1.8 Knowing things that don’t exist
Things which do not actually exist have truth corresponding to their potentiality (i.e. it is true that they are potentially existent.
Moreover, all that is known is known either through its likeness or through its opposite.
An intellect that is not in potentiality does not know privation. We should understand Aristotle's words as meaning that an intellect which is not in a state of potentiality does not know privation through a privation which it has in itself. And this agrees with what he had said just before, namely that we know a point, and every indivisible, by way of privation of division. The reason is that simple and indivisible forms are not in our intellect actually (i.e. not as known directly) but only potentially (i.e. as known indirectly); for if they were in our intellect actually they would not be known by way of privation. Substances that are not joined to matter know what is simple in that way. So, God does not know evil through a privation which he has in himself. He knows it through the contrary good.
Again, what is known not through itself but through something else is known imperfectly.
To know something only through something else is to have imperfect knowledge if the thing is knowable through itself. But evil is not knowable through itself, because evil of its very nature is the privation of good. So, it cannot be defined or known except through good.
1.9 Universals and Specifics
Our intellect does not know individuals precisely because of its freedom from matter. As Aristotle says, “the mind grasps universals; the senses grasp individuals”. Moreover, in ourselves the only powers of knowing which can grasp individuals are those which receive species which have not been freed from material conditions.
Our intellect abstracts intelligible species from individuating principles. So, an intelligible species in our intellect cannot be the likeness of the principles of individuals as such — which is why our intellect does not know individuals.
1.10 Knowing Infinity
An infinite as such is unknown. As Aristotle says, an infinite is “that of which, if one grasps a part, there is always something more to grasp”. Augustine also says that “what is comprehended by knowing is limited by the knower's comprehension”. But infinites cannot be limited.
The reason for this is that the extension of a knower's knowledge depends on the scope of the form that is its principle. Now in sense-knowledge the species is the likeness of one individual only; so only one individual can be known by means of it. But an intelligible species in our intellect is the likeness of something in its specific nature, which can be shared by an unlimited number of individuals. So, our intellect, through the intelligible species of human beings, knows in a manner an unlimited number of human beings; not, however, human beings in their distinction from one another, but in their common possession of their specific nature; for the intelligible species in our intellect is not the likeness of humans in what makes them individuals, but only in what makes the species.
As Aristotle says, “the notion of infinity coincides with that of quantity”; and the notion of quantity includes an ordering of parts. So, to know an infinite in its own nature is to know part after part; and in that way an infinite is not really known at all; for whatever number of parts is grasped, something always remains beyond.
“Going through” implies a certain succession of parts; and that is why an infinite cannot be gone through either by a finite or by an infinite. But the idea of comprehensive knowledge is satisfied if the knowledge equals the object known, for we say that something is known comprehensively when no part of it remains beyond the knower's grasp. So, it is not contrary to the notion of an infinite that it should be known comprehensively by something that is infinite. In that sense, we can say that what is infinite in itself is finite to God's knowledge (i.e. is known comprehensively by it) - though we cannot say this if we take “that which is infinite” to mean “that which can be gone through”.
1.11 Thinking about Contingent Events
To appreciate this we should note that we can think of an event as contingent in two ways.
First, we can think of it intrinsically and in so far as it is already actual. If we think of it in this way, it is not future but present, and it is not contingent with respect to different outcomes. It is determined to one outcome. As such, it can be the object of certain and infallible knowledge, as something seen is to vision (as when I see Socrates sitting down).
But we can also think of a contingent event as it exists in its cause. If we do that, we think of it as going to happen, as a contingent event not yet determined to one outcome (for a contingent cause can end up having varying effects). Considered as such, a contingent event is not something of which we have any certain knowledge. So, someone who knows a contingent effect only in its cause has no more than a conjectural knowledge of it.
We know successively things which become actual in time while God knows them in eternity, which is above time. So we cannot be certain when it comes to future contingents, for we know them precisely as future contingents.
To know propositions is proper to our intellect in its function of putting together and separating. Since our intellect has the power to form propositions, the way they are formed is by putting together or separating their terms in our minds. We pass from one object to another because the intelligible species in our minds represents one thing without representing other things. So in understanding the nature of people we do not thereby immediately understand what else is true of them. We understand them one by one according to a certain succession. For this reason we have to reduce to unity what we understand separately, by putting together or separating concepts to form a statement.
1.13 Theoretical and Practical Knowledge
We gain theoretical knowledge through abstraction from actual things. But theoretical knowledge is more excellent than practical knowledge, as Aristotle shows. Knowledge may be speculative only or practical only. Or it may be partly speculative and partly practical. We can see this by noting that we can call knowledge speculative on three accounts.
- First, from the nature of the things known, when they are not producible by the knower, for example, someone's knowledge of natural things or of divine things.
- Second, with respect to the mode of knowing - as, for example, when an architect defines, analyses and examines the qualities proper to houses in general. To do all this is to consider producible things, but in a speculative way, not as producible. Something is producible by way of the application of form to matter, not by way of a resolution of a composite into its formal principles considered universally.
- Third, knowledge can be speculative with regard to its end or purpose. As Aristotle says, 'the practical intellect differs from the speculative in the end to which it looks'. The aim of the practical intellect is production. That of the speculative intellect the consideration of truth. Thus, if builders consider how some house could be built, not with a view to building it but merely for the sake of knowing, their consideration, so far as concerns the end they look to, is speculative, though still about what could be produced.