Why this Question Matters
Having warmed up on the lower slopes of Ia.q84, it is time to ascend the Mount Everest that is Ia.q85. Aquinas has assembled the components of his theory of mind. If we were to carve a simple straight line through the theory, ignoring complications like memory then it would look something like this. The external sensory powers receive sensible species corresponding to their proper objects. The internal sensory powers assemble the data received by the external sensory powers in the expressed sensory species known as the phantasm. The active power of the intellect illuminates the phantasm and in doing so abstracts the universal intelligible species from it. The intelligible species is then impressed upon the passive power of the intellect. The expressed species of the passive intellect provides the conceptual material with which the process of intellectual reasoning begins.
It is now time for Aquinas to throw the strongest objections that can be found at his theory and to defend his theses against them. The first three articles in particular are intellectual tours de force. Whilst pondering these articles the reader might wish to consider that the objection presented to Aquinas’s theory should also be presented mutatis mutandis to any theory of mind. After all, one of the most remarkable things about human existence is that there is a subject, an “I”, experiencing intellectual cognition of external things and able to reflect on these experiences as a cognitive act in itself. How do things that exist outside of my mind come to exist inside my mind so as to enable me to understand them? Any theory of mind worthy to present itself in the public forum should be prepared to answer the type of objections presented here.
The Thread of the Argument
A1: The first article focusses on the abstraction of intelligible species from phantasms by the active intellect. The structure of this question makes it clear that Aquinas is focussed on a number of weighty objections rather than on a new exposition of the basic theory. His main answer merely differentiates between the three levels of cognitive power that one can find in sensory cognition, in angelic intellection and in human understanding. The object of a sensory power is a form as it exists in a material object; so sensory powers only have cognition of individual concrete particulars. Angelic intellection is through immaterial species that are connatural to them (Ia.q55.a2) and therefore their intellection of material forms is in themselves and in God, without any need for abstraction from the material. Human intellection stands in the middle of these: the human intellect is immaterial and therefore for a human to have an immaterial cognition of something that is material necessarily has to involve the abstraction of form. The only candidate for the object of such abstraction is the phantasm produced by the sentient powers of the soul.
The first objection argues that, if the intellect were to abstract the intelligible from phantasms, rather than directly from the material object, then it would not understand the material object but rather a representation of the object. Aquinas counters by making a distinction between two modes of abstraction that will enable him to identify where error might happen in the process of abstraction. The first method of abstraction involves abstracting things in relation one to another (he calls it the mode of composition and division); this mode allows for error when we abstract relationships that are not abstracted in reality. The second mode of abstraction (the mode of simple and absolute consideration) involves pulling apart things that are not abstracted in reality and considering them in absolute rather than relational terms. For example, we can consider the colour of an apple in isolation from the fact that it is the colour of this apple. This form of abstraction involves no error whereas the first form of abstraction, which might lead us to say for example “the colour of the apple is separated from the apple”, can involve error.
Aquinas claims that the abstraction of intelligible species from a phantasm involves the second mode of abstraction: considering the nature of the material object which is being abstracted from, rather than any individuating principles that remain represented in the phantasm. Error can occur in abstraction when it is done in such a way as to misrepresent reality; but it does not occur simply because the mode of existence of forms of material objects in the soul is different from the mode of existence of those forms in reality. The forms of material things existing in the soul are the forms of those material things and therefore provide us with a sound basis for intellections.
The second objection observes that material objects are, by their very definition, material; since the process of abstraction from phantasms involves abstracting the universal from the particular, taking form away from matter, then this would seem to mean that we cannot actually understand material things as we’ve removed part of their very definition from them. Aquinas replies to this distinguishing between common matter and designated matter. The former is matter considered in general and the latter is matter considered in particular; the example that Aquinas gives distinguishes between flesh and bone and this flesh and these bones. When perceiving, for example, a human being, the process of abstraction from phantasms involves abstraction from the particular designate matter of this flesh and these bones but not from the common matter of flesh and bone. We understand material objects in the fact of their materiality but abstracted from the particular designate matter out of which they are formed.
Aquinas takes this opportunity to go further: in the case of mathematical species we can abstract even further, removing consideration of many sensible qualities. Mathematical entities are abstracted considering them only with respect to quantity, which Aquinas calls the level of common intelligible matter. They are thought of in isolation from this or that substance, that is they are abstracted from what is called individual intelligible matter. When we go beyond the mathematical, considering things like being, one, potentiality and actuality, then we go even beyond this form of abstraction considering such types of things completely in isolation from matter.
The third objection turns to the idea that phantasms could act on the passive intellect in the same way that sensible qualities act on the corresponding organ of sense. There seems to be no need for the active intellect and for a process of abstraction if the phantasms do all the work. Aquinas identifies the key problem with this idea as the fact that phantasms exist in the material bodies that are the sense organs and that the passive intellect is purely immaterial. As the material cannot directly affect the purely immaterial, there must be an immaterial active principle (the active intellect) responsible for getting the appropriate information from the phantasms to the passive intellect. Aquinas builds on this answer in the replies to the final two objections, describing further the action of the active intellect. The active power of the active intellect illuminates the phantasms rendering them suitable for the abstraction of intelligible species by joining the power of the intellect to the powers of the sentient soul; the process of abstraction extracts the natures of the species of what is being considered without their individuating conditions and impresses them on the passive intellect. The intellect understands the object of perception by turning back to the phantasms in the context of having abstracted the quiddity of the object from the phantasms.
A2: The active intellect abstracts the quiddity of the object of cognition from phantasms presented to it by the sensory powers. The intelligible species extracted by this process of abstraction are then impressed upon the passive intellect. But if what is present in the passive intellect are intelligible species and if it is these only that the passive intellect has for the understanding of things, does this not mean that it is the intelligible species that are understood rather than the object of cognition from which these intelligible species originally arose? The arguments of the three objections are all related to this type of reasoning; and this objection is itself a variant of the objections of the first article as related to the abstraction of intelligible species from phantasms rather than directly from the object of perception. The counter position that Aquinas wishes to argue for is well laid out in the sed contra: just as the sensible species are that by which the sensory powers sense, so the intelligible species are that by which the intellectual powers understand the objects of cognition. In both cases, the respective species are instruments. Sensitive species are not sensed, intelligible species are not understood; sensitive species are that by which some external object is sensed, intelligible species are that by which some external object is understood.
Aquinas advances two arguments against the position implied by the objections and gives an argument in favour of his position. In the first place, if the knowledge we have of things was purely of species that exist in the soul, then this would apply to things about which we have scientific knowledge; to Aquinas, this seems obviously wrong as scientific knowledge is about the external world. The second argument is that such a position must inevitably lapse into a radical subjectivism: “whatever seems to be the case is true”. If knowledge simply is of what is inside our heads, then whatever is inside our heads is all that gives rise to knowledge.
In favour of his own position, Aquinas takes the lead from Aristotle’s Metaphysics 9. We can think of two actions: one which remains within the agent (like thinking) and one which passes into a patient (like cutting a log). Both actions stem from some form, and in both cases the form must possess some sort of likeness to the object of the action. The form of cutting is a form of cutting that log over there; the form of thinking is the form of thinking about that log over there. So the form, that is the intelligible species, of the log that we are thinking about, is precisely the form of the log and the intelligible species is a sort of likeness of the log by which we think about the log. We can, of course, reflect upon our own act of intellectual understanding. In doing so, we will understand both our act of understanding and the intelligible species by which we do that understanding of our understanding! It is in this secondary sense that we can say that intelligible species can be the direct object of intellection; but still, the primary sense of intellectual understanding is of the object for which the intelligible species provide a likeness.
When we perceive a human being, their human-ness is apprehended in our intellects without individuating conditions; the intelligible species provide a likeness of the human-ness without there being a likeness of the individual.
The reply to the third objection introduces the important notion of an expressed species. When the sensory powers receive sense impressions from some external object, the object acts upon the organs of the sensory powers. The power of the imagination then forms an expressed species (the phantasm) from what has been impressed upon the sensory powers by the external object. The same sort of thing happens in the intellect. The passive intellect is acted upon by the impression of intelligible species. It then forms an expressed species which is called the concept or word. In this way the process of intellection comes to sort of terminus connecting with our linguistic reasoning processes. The concept may be expressed in language; the uttering of a sentence connecting words represents the intellect’s process of composition and division by which we reason about things.
A3: Aquinas has established that the intellect comes to understand the quiddity of things by means of the active intellect abstracting the universal from the phantasms presented to it by the sensory powers. The question that Aquinas wishes to address in this article is whether there is some sort of ordering of universality in the intellect. So, when we are looking at a human being, is the more universal notion of animal in some sense prior, or posterior to the notion of the universal human being?
Aquinas answer that when we think of sensory cognition, then certainly we have cognition of singulars before the intellect gets to work to give us cognition of universals. In this sense then, the cognition of what is less universal is prior to what is more universal. But when we consider the intellect as it moves from potentiality to actuality in its act of intellection, we realize that it moves from a state of incompleteness to a state of completeness the better we understand the object of cognition. The terminus of this act of intellection is complete scientific knowledge of the object of cognition; before we reach this state (if we do), our incomplete knowledge is still a bit murky in places. The indistinctness lies in our ability to first grasp a sort of universal whole, with all its parts considered integrally, without grasping the quiddity of those parts that make up the whole. Our grasp of the universal whole is less distinct but more universal than a grasp of the whole considered together with its parts. So, when we perceive something as an animal, without understanding that this animal is a rational animal, we grasp something more universal prior to coming to an understanding of a less general universal. In this sense, then, the more universal is prior in our intellects to the less universal.
In the reply to the first objection, Aquinas identifies two ways in which we can consider universals that might confuse us when considering universals in the context of cognition. In the first way the universal is considered alongside its intentionality; that is, together with the fact that a particular universal has a relationship to all the things from which it could be abstracted. The universal horse has a relation with all actual horses, for example. If we consider universals together with their intentionality, then the more universal should be considered posterior to the less universal. Since we grasp the intentionality of a universal by repeated acts of cognition, we arrive at the scope of the less universal’s intentionality sooner than for the more universal. If, one the other hand, we consider the universal as universal without any notion of intentionality, then in nature we find two possible orderings. In the generation of things, the more universal is prior to the less universal, so that animal comes about before human. On the other hand, in the ordering of perfection actuality is prior to potentiality and therefore the perfect is prior to the imperfect and the less general prior to the more general.
A4: Can we have an intellectual understanding of more than one thing at a time? It would seem that we must be able to: after all, if we’re to understand wholes that are made up of parts, and if we’re to be able to make comparisons between different things then we must be able to hold multiple things in our intellects simultaneously. Also, as the second objection puts it, there doesn’t really seem to be any good reason to deny it as a possibility.
Aquinas thinks differently. It’s impossible for a single intellect to be brought to actuality by more than one form simultaneously, just as something cannot simultaneously be informed with the form of an apple and the form of an orange. The intellect can have intellectual understanding of many things simultaneously provided they are grouped together under some single form. This even applies to God’s intellect: He has simultaneous intellectual knowledge of everything through the single form of His substance.
When we think of the parts of a whole, we can think indistinctly of the parts as they exist in the whole; so we think about the house and the bricks out of which it is built are grouped together in the background under the form of the house. If we think distinctly about the parts of the whole, then we lose immediate sight of the whole; if we think of a brick, we are not thinking of the house. Similarly, when we make a comparison between two things, we hold both of the things in the intellect under the form of a comparison; there’s a sort of whole composed of the two things, rather than the two things individually considered.
A5: Human intellectual understanding of things in the world is progressive; there is always a passing from potentiality to actuality involved. When we apprehend something, we apprehend it in stages one aspect at a time. So, in seeing Socrates in the distance we may very well go through a process rather like this: we firstly apprehend him as being a living being and very quickly after that recognize him as a human being. On seeing the components that make up his face, we recognize this human being to be Socrates. We notice that he is wearing a white robe and that he has leather sandals on his feet. This process involves the apprehension of various quiddities together with a successive composition of and division between them. For example, when we apprehend that Socrates is wearing a robe and we apprehend the robe’s whiteness we compose the notions of Socrates, of white, and of robe to arrive at the conclusion that Socrates is wearing a white robe. Similarly in recognizing Socrates by seeing his face we compose the notion of human being with our notion of Socrates but divide off the notion of human being from everybody else that we recognize but Socrates. Thus, in human intellection a process of composition and division of concepts is a key part.
This process of composition and division that humans have to go through is in marked contrast to intellectual understanding in the angels and in God. The latter do not have to gather their intellectual understanding of things from the senses and therefore do not have to put concepts together in the same way. The intellectual understanding of angels arises from forms connatural to them and infused at their creation; that of God is His very substance.
The third objection argues that in the real world things simply are the way they are: the ball simply is white. There are no processes of composition and division in the world of things that corresponds to the intellect’s processes of composition and division. Aquinas concedes that the likeness of an external object is received in the intellect in a mode of being that is different from the mode of being of the original thing. So, it not surprising that even though there may be in the external object something that corresponds to the intellect’s composing and dividing, it is not present in the object in the same way as it is present in the intellect. However, we can still identify the composition of form and matter in the external object with the composition of a universal whole with its part in the intellect and the composition of subject and accident in the external object with the composition that corresponds to predication in the intellect. So there is a correspondence between the sorts of composites that exist in the external world with those that exist in the intellect. This correspondence is what enables us to maintain that the likeness as it exists in the intellect is faithful to the external object.
A6: In his de anima chapter 3, Aristotle makes the astonishing claim that intellective understanding is always correct. Since it is manifestly clear that we can be mistaken about things that our intellect considers, we must enquire into what Aristotle, and Aquinas following him, means.
Aquinas argues that we should observe the parallel with the sentient powers. The external senses, when they are not impeded, are never mistaken about their proper object. The sensory powers can still make mistakes, of course. When the sensory powers infer things about the common sensibles, for example, they can be mistaken. But these types of mistake arise because, in these cases, the proper objects of the sentient powers are not what are under consideration. When we consider the intellect, restricting attention to its proper object, that is, to the quiddity of things, then the same considerations apply. The intellect can make mistakes, but it makes those mistakes in composition and division. The actual process of abstraction, the proper object of the intellect, does not fail provided that the intellect is not impeded.
Consequently and again, provided it is not impeded, the intellect cannot be mistaken about first principles and about immediate consequences of those first principles. These provide examples of things that are known immediately to the intellect in their quiddity and therefore are sure.
A7: If the intellect is infallible in understanding its proper object, grasping the quiddity of things, does that not mean that the intellectual abilities of all humans have to be identical? After all, either one grasps the quiddity of something or one does not; this is something that does not admit of a greater and lesser. This seems to be in conflict with the common observation that intellectual gifts differ from person to person!
Aquinas observes that, from one point of view, the argument is sound. We do either grasp the quiddity of something or we do not. On the other hand, form is received in matter according to the disposition of the matter; therefore a more powerful soul is received in a more suitable body. In addition, the sentient powers of the soul depend upon matter for their functioning; as they support the intellectual powers in the latter’s operations, they may do so for better or worse depending upon their fitness for purpose. Following the argument of the sed contra, these arguments indicate that some can think more deeply than others about the objects of intellection.
A8: Some things appear to be indivisible, in the sense that although we may be able to conceptually divide them into parts, they themselves do not exist except as a whole. Aquinas identifies a continuum as such an indivisible thing; we may be able to conceptually break it apart into points but those points only exist in potentiality in the continuum, as it were. Similarly the human reason: we may understand it in its different powers, but it is a unity in itself. In the cognition of such indivisibles, Aquinas argues that we grasp their quiddity as indivisible prior to being able to think about how they may be divided into parts. On the other hand, there are some types of indivisible that we can only define in terms of privation. A point, for example, is defined as that which has no parts. For indivisibles like these, we have to grasp their quiddity through grasping the quiddity of the privations involved. Therefore we have cognition this type of indivisible posterior to having cognition of the divisible.
- The forms of material things that exist in the soul are the forms of those things and not only a representation of them. Therefore we have a correct understanding of reality by abstraction from phantasms because this process of abstraction involves an absolute consideration of those forms as they exist in reality.
- When the intellect abstracts form from matter, it abstracts from this particular matter but not from matter in general. The abstraction retains the fact that the form informs matter.
- Sensitive species are that by which some external object is sensed, intelligible species are that by which some external object is understood.
- The expressed species of the intellect form the raw material with which we carry out the process of thinking. Our process of thinking is a complicated process of composition and division of different intelligible species in the passive intellect. We put ideas together and pull them apart repeatedly until we get something true that corresponds to reality.
- In sensory perception we grasp the singular before the universal, but in intellectual cognition we grasp the more universal before the more particular. However, when we consider the universal in regards to its intentionality, the situation becomes more complicated. We arrive at the scope of the less universal before we arrive at the scope of the more universal; each by means of repeated acts of cognition.
- As concerning the direct object of cognition, we can only have one object of cognition at a time. When we consider a complex object, or an object in relation to some other object, we consider them under a single form of the complex.
- The intellect is infallible in the cognition of its proper object in a way parallel to the fact that the sensory powers are infallible in the perception of their proper objects. The proper object of the intellect is the quiddity of the object of perception. When we make mistakes in our intellectual understanding of things, it happens further along in the process of intellection. It happens when we make mistakes in the composition and division of the concepts expressed by the passive intellect.
- Although the intellect is infallible with respect to its proper object, this does not mean that everybody has the same level of intellectual ability. The sensory powers depend upon material organs and therefore may be more or less able in the complex process of cognition. Different people may have different abilities with respect to the composition and division of expressed intelligible species.
- Aquinas never really gives us a systematic account of where error might happen in perception and cognition. He identifies infallibility in the senses sensing their proper objects and in the intellect perceiving the quiddity of things, but he doesn’t tell us explicitly where and how things can go wrong. Error would seem to crop up in the way in which sensible species and intelligible species are composed and divided within the sentient and the intellective soul respectively. The interior senses can make mistakes concerning how the basic sense data is interpreted at the level of sensation; the intellect can reason falsely about the relationships between different intelligible species, coming to incorrect conclusions.
- The fourth objection to the third article argues that we arrive at our knowledge of causes and principles through our knowledge of effects and that therefore the more particular must be prior to the more universal in our intellects. In the final paragraph of his answer, Aquinas states that this is not necessarily the case: sometimes we understand unknown effects through their causes. However, the rest of the answer seems to be rather odd; bypassing the actual objection and focussing on the various ways in which universals can be principles of things.
- In the fourth article Aquinas denies that we can have simultaneous intellectual understanding of a multiplicity of things. Although his argument is reasonable, it’s a bit frustrating that he doesn’t say more about the mechanisms by which we do hold multiple things in mind. When performing a comparison of two things, we consider first one and then the other and then hold them both under the form of the comparison itself; but what goes on in detail in this consideration? Perhaps it would have been helpful for him to argue that when we consider a composite object (and after all, most things we consider is composite in one way or another) we can only consider them intellectually under one aspect at a time.
- Aquinas flirts with the boundary between the intellectual and the linguistic (for example in the fifth article) in ways that make one wish that he had gone further. The result of the intellectual process of abstraction from phantasm is an impressed intelligible species in the passive intellect. The corresponding expressed species is the concept or word; these expressed species are then the raw material of processes of composition and division but also of the linguistic expression in words of what is inside our heads. If one were to follow through the chain of events in the process of sensation, cognition and expression one should arrive at a complete theory of how our linguistic expressions correspond to the world.
- In the third objection to the fifth article an argument is put forward that can be developed into a powerful criticism of Aquinas’s systematic exposition of mind. In the real world things simply are the way they are: the ball simply is white. There are no processes of composition and division in the world of things that corresponds to the intellect’s processes of composition and division. The more general criticism is that we want things in the mind to be the same way (an accurate representation, perhaps) of the way that they are in the world. But to get into the mind, there has been a process of sensation, in which individual senses take apart the object of perception, only for it to be put back together by the internal senses in the phantasms. The phantasms then undergo a process of abstraction whereby various quiddities of the external object arrive in the passive intellect. A final, but on-going, process of composition and division then sticks all these quiddities back together again in true concepts about the external object. Don’t all these processes of taking-apart and then gluing-together come between us and the world? Perhaps the key to answer this objection is Aquinas’s claim for the infallibility of the senses in sensing their proper objects and of the intellect in abstracting the quiddity of things. The senses and the intellect are able to provide a faithful representation of what is out there in the external world; we are capable of error in our assessment of these data but we do have the capability to arrive at some true scientific knowledge of the world.
- Aquinas does not tell us what could impede the intellect in the intellection of its proper object. In the case of the sentient powers, physical damage or illness could account for impediment as these involve a material organ. What might impede the immaterial intellect?