Just Thomism

Lydia McGrew argues that the problem of evil poses a substantial problem for natural theology. If we take, say, the famous trilemma of pseudo- Epicurus

If God is willing to stop evil but unable, how is he omnipotent?

If he is able but not willing, how benevolent?

If willing and able, how is there evil?

we can read it as showing that Christian and natural theology come to different conclusions about whether God is benevolent or indifferent with respect to the world. It seems that natural theologians are forced to conclude that God is indifferent, and that they must confess frankly that they stand in need of revelation in order to establish the crucial fact of Christian theology that God loves the world and desires to give good things to human beings. While she initially poses the problem with respect to the problem of evil, a more forceful way of putting McGrew’s argument (which is implied in how she develops the point in the comments) is this:

In order to defend God’s benevolence in the face of evil, one must be told God’s plan to remedy evil, but

God’s plan to remedy evil belongs to the history of salvation.

Salvation history is known only by revelation, therefore, etc.

The argument admits of more than one interpretation, and I need some groundwork in order to respond. The argument is a general argument about what reason can know purely by itself, and I think this question is usually understood poorly, and needs to be visualized in a better way.

St. Thomas argues that God needed to reveal even things that can be known by natural reason, since the truths which can be known about God were known only by few, after a long time, and with much error. It’s crucial to notice that this state continues throughout all time. Natural theology or metaphysics are the most difficult of sciences. Almost no one can learn them at all, and of those who can, none can learn them quickly and all commit many errors. The sense we have that we can attain certainty early and easy is not entirely illusory, but this certitude depends on our practicing metaphysics in a safe environment that doesn’t expose us to the full force of all possible objections from the beginning. Example: a flower kept in a greenhouse will really survive all the shocks and stresses it encounters, and in this sense it survives “by its own nature alone”, but it is not exactly in its natural place, and it wouldn’t survive at all if exposed to all possible stresses or strains we could inflict on it. The power of “pure reason” is like the survival power of a flower: it needs an environment that not only protects it not only from what it might encounter in it natural environment, but also from things that, while not part of it natural environment, might be introduced to kill it off (like pesticide). Institutions – normally churches and institutions affiliated with them –  provide this environment. The proof of that the environment is the correct grows as the person nurtured in it finds himself able to assimilate more and more truth, and overcome more and more objections.

Even after metaphysics becomes strong enough to live on its own, there is another difficulty in that its truth is found only in the soul of the one studying it. There is no product that the metaphysician can produce to prove the truth of his efforts and no planes crash if he is wrong. The metaphysician is seeking just truth and knowledge, and both are interior perfections that no one experiences except the one who has them.

The question of what we can determine by pure reason is set against this backdrop. If we understand the question of what reason can know by itself to mean “what can a reasonable person expect to know about metaphysics if he tries real hard to figure it out for himself”? then the answer is “almost nothing”. A person might present this “almost nothing” in a dogmatic or bull-headed way, or bully their way through objections, but this doesn’t change that they know.

Taken in this way, what is proper to McGrew’s question drops off and we see it in light of the general difficulty of all questions in metaphysics or natural theology. All natural theology is hard, it requires exterior help, and when pure reason finally succeeds fully, it is only within the soul of the one knowing, who is aware of how arbitrary his doctrine must look to anyone who has it presented to them in their natural habitat, or (what is quite common nowadays) from the pesticides that we introduce artificially to kill off even those plants that might have survived in the wild.

The claim that the rational or scientific part of man is an effect of a deeper cause or causes is a very old claim with many variations. Chesterton quipped that “reason is based on faith”, Alisdair Macintyre has convinced many that philosophical discourse is at least in large part an emanation of non-philosophical forces, Aristotle posited a separate cognitive power and virtue (nous) as a foundation of rational discourse, and the following claim from the official summary of Shermer’s Believing Brain ought to sound familiar:

We form our beliefs for a variety of subjective, personal, emotional, and psychological reasons in the context of environments created by family, friends, colleagues, culture, and society at large; after forming our beliefs, we then defend, justify, and rationalize them with a host of intellectual reasons, cogent arguments, and rational explanations. Beliefs come first, explanations for beliefs follow.

William James gives a related account which is ultimately the complete contrary of Shermer’s:

[I]f we look on man’s whole mental life as it exists, on the life of men that lies in them apart from their learning and science, and that they inwardly and privately follow, we have to confess that the part of it of which rationalism can give an account is relatively superficial. It is the part that has the prestige undoubtedly, for it has the loquacity, it can challenge you for proofs, and chop logic, and put you down with words. But it will fail to convince or convert you all the same, if your dumb intuitions are opposed to its conclusions. If you have intuitions at all, they come from a deeper level of your nature than the loquacious level which rationalism inhabits. Your whole subconscious life, your impulses, your faiths, your needs, your divinations, have prepared the premises, of which your consciousness now feels the weight of the result; and something in you absolutely knows that that result must be truer than any logic-chopping rationalistic talk, however clever, that may contradict it. This inferiority of the rationalistic level in founding belief is just as manifest when rationalism argues for religion as when it argues against it.

James’s emphasis on the word knows crystallizes the problem of speaking about this level from which reason arises. Does James mean that it actually knows, that is, it grasps the truth of things? Or is he merely speaking of the conviction that we have of the truth, quite apart from seeing any truth at all?  The two states are as contrary as wisdom and fanaticism. The quick answer that both arise from the level that causes reason is more facile than illuminating- and it is probably impossible to uphold this, since it is hard to see how a voice that spoke both wisdom and folly could be said to speak wisdom at all. Another quick answer is that we can and should subsume or critique the level that causes reason under a rational critique. Such a desire is an obvious contradiction, which only succeeds by positing some standard (science! confirmation!) that is separate from the ocean of causes giving rise to reason. The simplest answer – that reason is nothing other than the systematization of fundamentally irrational causes, also fails to account for experience.

It’s striking to notice just how superfluous truth is. Truth is not just a judgment, but an affirmation of how this judgment stands to us with respect to its truth, and such an affirmation adds nothing to the practical value of the judgment or even the fact of the thing judged. Animals, for example, maneuver their way through the world just fine without giving any sign of recognizing that the information they are working from is true. A monkey jumps from one branch to another or fishes termites out of a hill without ever noticing that it is true that he can reach them, and truth would not, in fact, help it judge vines any more effectively or find any more termites.

The superfluity of truth is not confined to practical truths. What does truth add to the idea that two and two are four, or that the earth goes around the sun? Truth is something in addition to these facts  (even if it is not another proposition over and above the proposition judged to be true) but the fact seems to exhaust all that is relevant to know, whether in the practical or speculative order.

Truth only matters to the extent that a subject decides to involve himself in a fact, and chooses to see this involvement as something in addition to the fact.  Truth is to this extent something over and above fact. The paradox is that while it seems to be the most superfluous and unnecessary thing, it is consistently judged to be a thing of the greatest value. One would not die for the facts or swear an oath to uphold them.

Any sensation is pleasant, but the pleasure is not an object nor a feature of the thing sensed taken by itself.

You taste an apple but you know the taste isn’t in it.

You walk into a room and put one and on a cloth couch and another on a granite coffee table. The coffee table is “cooler”, though everything in the room is the same temperature. It’s cooler when you walk into an air-conditioned room than after you’ve been there for two minutes.

You see something pink, then get closer and see it is red and white squares. Would it be “real” pink if you made the squares small enough? Bees (under UV light) see sunflower petals as having two colors. We see one. Who is right?

It is hard or soft only relative to strength. A chickadee experiences an ankle-thread like we experience steel leg irons, a newspaper could crush an insect in a single light stroke, spider webs are as fatal as tar pits in the insect world.

The same applies to large and small, which Aristotle knew were subjective too.

Aristotle again: rough and smooth are subjective, for they relate to the arrangement of parts relative to us. But shape is an arrangement of parts too.

The unity of motion over time is essentially depended on the memory of the subject; but motion is a unity over time.

Bees and men see things under different lights, and neither light is the true one. What is the basis for the truth of waking experience as opposed to dreams?

Huxley: no one mode of subjectivity has any intrinsic value over another. Chemically altered consciousness is no better or worse than “standard” consciousness. Each has it benefits and limitations.

Melancholia is now depression – but it has always been allied with genius and great art. Who then can call it a disease? It has value in some contexts and not in others. I celebrate my disease.

If we can celebrate disease, why not deviancy?

Whether it is universally true that “more and less are attributed to diverse things insofar as they approach, in diverse ways,  to something which is most such (magis et minus dicuntur de diversis secundum quod appropinquant diversimode ad aliquid quod maxime est)

Objection 1: Greater or lesser is nothing other than a relation between two terms, and so it suffices to know the two terms to know their relation. It is superfluous, therefore, to relate any two terms to some third which is most such.

Objection 2: Greater or lesser is possible in instances where a maximal is impossible, as is clear in a numerical sequence. It is therefore impossible for the principle to be universally true.

Objection 3: What is most such can be taken in two ways: as merely possible, or as actually existing.  Now in no created thing does the possibility of X require the actuality of X. The principle therefore is not verified as true in the physical world, since there is no necessity that what is most such exist in this order; and so a fortiori it cannot be a universal principle of all things allowing for a metaphysical proof.

Objection 4: Contraries are in the same genus. But St. Thomas applies this principle to the good and true, and so in its universal application it must also apply to the contraries of these things, namely the evil and the false. The proof therefore proves an “Anti-God” – which is at least unfitting, and perhaps even negates the possibility of God.

Objection 5: The refutation of confirming evidence for something counts as evidence against that thing. But St. Thomas gives as confirming evidence for the principle that “what is more hot approaches what is most hot”, which was based on the false belief that fire was the hottest possible thing and all other hot things derived their heat by being mixed with fire. St. Thomas’s own words therefore count as evidence against the principle he cites.

Objection 6: What is most such is either known entirely in potency, or in some way actually. If the former, then what is most such is simply unknown, since the one who knows something only potentially is ignorant of it. If we know what is most such actually, however, then we know what is more perfect and knowable in itself prior to what is less perfect, which is utterly contrary to the principle that Aristotle and St. Thomas articulate everywhere: what is most knowable  in itself is least knowable to us.

Response: The oldest interpretation of this principle sees what is most such as an exemplar cause of what is more or less. The interpretation which stays closest to St. Thomas’s doctrine of exemplar causes is this: An exemplar cause is that form by which an efficient cause brings forth its effect. But St. Thomas has already proven an order of efficient causes, and it therefore follows that there is an order of exemplar causes. St. Thomas chooses those forms given in experience whose exemplars are “what all call God”, namely, “good, true, and the like”, even though he does not directly claim that God is the supreme good in this proof – most likely because “supreme good” is too ambiguous. Considered in isolation, “the supreme good” is more a subject of controversy than “what all call God”, since if when one asks what it is the answers tend to be various – some say pleasure, others wealth, others fame and reputation, etc. Nevertheless, in the context of a series of exemplars in agents, it is clear that “supreme good” requires the existence of some being deserving to be called divine, since any agent that dispensed the supreme good to others would tend to be called divine by them.

While this proof is sound it does not seem to be the intention of St. Thomas in the fourth way. First, there is no reference in the proof to any previous proof or to the order of agent causes. Second, while it is true that all of the five ways are given in more or less summary and perfunctory fashion, this does not extend so far as to let us assume that St. Thomas is omitting to mention the very basis he is arguing from. In fact, a summary more tends to restrict itself the very essential bases that one is arguing from. Again, a summary might leave out various objections or refinements, but it cannot leave out the whole basis of ones argument. The same arguments apply to those who claim that the fourth way proceeds from an implied doctrine of participation, though this is closer to the truth so far as we know that St. Thomas considers the text he cites from Aristotle in the fourth way as an example of participation. Still, like most accounts of the fourth way, the Participation” account does not explain the proof but replace it with one that is similar but not identical, nor faithful to the letter of the text.

The axiom in question is a statement about the more and less, and the more and less are taken from quantity. St. Thomas is clear that quantity is of two kinds: that of number/extension and of power. Since St. Thomas is trying to argue from creatures to God, he is clearly only interested in a “more and less” that corresponds to or arranges things in some sort of hierarchy, and so he is not interested in the first sort of quantity but the second.

The quantity of power is nothing other than act considered as having the power to actualize some other. This power can be taken in either the order of ends or of agents (since both agents and goods have the “power to move”), though St. Thomas here seems to be prescinding from this division and considering only virtual quantity or act as communicative to another. The intention of speaking of “more and less” is therefore to speak about what is more or less actual, and in the order of act the most actual is not only first in being, but even the first in our knowledge, so far as we can only know what is potential through what is somehow actual, which is why it is true even in the noetic order that the actual, as actual is known first, even if that which we know first absolutely is not what is most actual absolutely.

Response to 1: The potential is always known through the actual, and therefore the imperfect by the perfect. So far as any two members are considered as imperfect – even if this is to a greater or lesser degree – they are known in relation to something perfect.

Response to 2: This objection is taken from the greater or lesser of numerical or extensive quantity and not from the quantity of power or act.

Response to 3: Since existence is a perfection of every possible perfection, then so far as a created being can either exist or not exist it is imperfect and therefore both is and is known in relation to some more perfect being, who is by definition a creator. In the measure that we do not know the creator, so also we do not know the full extent to which the creature is undetermined to being or non being.

Response to 4: Evils are known by the negation, impeding, or destruction of something desirable, and so are greater or lesser in relation to what is a greater or lesser good, not a greater or lesser evil.

We concede objection 5.

Response to 6: Being is the first thing known by the intellect, but this can be taken in two ways. So far as our intellect moves from potency to act being is to be taken as what is most potential and imperfect. But being is also divided into potency and act, and act must be known before potency. It follows that the first thing the intellect knows is in one respect the most imperfect and in another sense the most perfect and formal, even though it is not necessary that we grasp being as actual in the fullest possible way since we do not understand the full extent to which the first concept of our mind is imperfect. Man’s failure to have an intuitive vision of pure actuality is also the reason why he cannot understand the full extent to which the first concept of his mind is imperfect. Nevertheless, our ability to grasp the imperfection of the created order is made in virtue of some intuition of that which is most actual and divine, even in our first grasp of being. This grasp is not by way of abstraction, nor can it be considered to be a properly human way of knowing, which is why St. Thomas did not include it in his formal account of human knowledge. We must nevertheless admit with Aristotle that there is something truly divine in man which most completely is man, that is, that there is a principle of his knowledge that is (as St. Thomas puts it) borrowed from God.

I attended a lecture today by Dan Toma, a biology professor who moonlights (with some big-enough names in Catholic Philosophy) as a teacher of what he argues is the Catholic view of the universe, and who claims that the findings of modern and contemporary science can be easily put in terms of this Catholic view. The dominant feature of this view is a hierarchical structure of the universe, ascending from the non-living to the living, and through the various grades of life from the material to the immaterial. Dr. Toma spent much of his lecture articulating the hierarchical theory of the Pseudo-Areopagite and speaking about the various developments that St. Thomas made to it. Dr. Toma argues that this theory of the universe was the common one until the Renaissance, when it was replaced by a different and conflicting view of the universe which reduces all things to material parts. I raised some of these objections in the Q+A (FWIW, I raised only #2 and #3 below. I wasn’t a Q+A time hog).

1.) We change our views of the universe when our old views are no longer persuasive. This persuasion might be forced or resulting from ignorance, but as a view becomes more and more long lasting and widespread, it becomes less and less probable that those who hold it are simply dupes, and the medieval view has been dead for at least 500 years. At the bare minimum, we need to appeal to some pretty subtle causes to explain how it didn’t deserve to die.

2.) The cosmos is a place or places, and so a hierarchy of the cosmos requires a hierarchy of places. In the ancient and medieval view of the world, there was such a hierarchy: the earth was in the well-defined center place and was the place of change, straight motion, and corruption; and the heavens were a place of circular motion, intrinsic immutability, and circular motion. The only way we can have a hierarchical universe now is if we say (a.) place is not significant to the universe, so it is not important that there is no hierarchy of place or (b.)  the sort of natural places it still makes sense to speak about (the womb as a place of a baby) can tell us something significant about the universe as a whole or (c.) we need an entirely different account of place. The first two options are dead-ends, the latter requires a great deal of work that I don’t see being done.

3.) While there is still a clear hierarchy in the Cosmos running from the non-living to man, this does not appear to be due to any causes within the Cosmos (St. Thomas was uncertain what cause was responsible for this order of species). Even if we decide to call selection and drift causes (which is not the easiest thing to do, given the role that chance plays in the process) they are only causes of the multiplicity of species and not of a hierarchy or order.

4.) The ancient and Medieval world had intricate accounts of the causal hierarchies that obtained between the heavenly “spheres” and the corruptible world. Such hierarchies are no longer discernible in the universe taken as a whole. There do not appear to be any equivocal causes in physics, and if there are they play a minor role. The sun cannot be said to cause generation as such, Saturn no longer causes the conservation in things, nor is the warlike temperaments caused by being conceived under the influence of Mars. This does not mean, as some have suggested, that St. Thomas’s first way collapses, but it does mean that the sort of hierarchy among mobiles that St. Thomas believed was manifest to sensation is no longer discernible in the universe as a whole.

5.) There is some reason to question whether our ascent to God should run though physical science at all. It was all well and good for Aristotle and St. Thomas to build so much physical science into their philosophical accounts of the world – they had never seen a system of physical science collapse under refutation. We contemporary people have seen two systems collapse: Aristotle’s and Newton’s. Do we even want to work the accounts of physical science into discourses about God and the loftiest things?

6.) It is not clear to what extent contemporary science seeks to understand the world. Such understanding is obviously one of its goals, but there seem to be other goals too which are not altogether compatible with pure understanding. There are a good number of noble lies that every scientist works with for the sake of making things, building a system, gaining power over nature, etc. “Noble lie” is jocose – in fact all they are doing is using dialectical definitions as opposed to searching for definitions of the precise nature of the thing studied. This dialectical way of proceeding makes it difficult for the one who wants to know “what is X?”  Too often, the scientific answer to such a question is “I dunno…but let me show you what I can do with it!”

7.) While metaphysics is an account of reality that is distinct from physics, everyone is rather vague as to how our mind gives rise to it. No one has yet given an adequate account of how “separation” or “the third degree of abstraction” can give rise to a concept of transcendent reality as opposed to a vague grasp of physical things (the best account was perhaps Aristotle’s, when he said that there is a divine part of man, which most is man, though he gave no details of the mode of knowing that gives us being as such).

Nick does an excellent job at presenting Russell’s problem of induction:

[Russell] noted that, logically speaking, no set of existential statements can entail a universal statement.

Existential statements are those of the form “there is a bat in the pantry”, or “there are fifty bats in the pantry”.  Russell noted, glumly, that no matter how many bats you observe in that pantry, you can never validly conclude that “all bats are in the pantry”. (“The Philosophy of Logical Atomism”, 1956)

This is a serious problem, because we use universal statements all the time, particularly in the case of scientific laws.  To take a simplified, somewhat banal example, physicists do not generally say things like”all 6,454,934 objects I have so far observed on planet Earth have fallen to the ground unless impeded by some other object or force”.  Rather, they say things like “mass attracts mass”, the idea being that a massive object like the Earth will always pull objects towards its center.  This is a universal generalization, a law.  The problem of induction revolves around the essential difficulty in deriving such laws from a collection of individual instances.  It is a pressing problem because our most successful model of epistemic activity, modern science, requires the articulation of universal generalizations or laws.

Yet, as Russell observed, the problem looks even more threatening in its logical form.  Insofar as we are empiricists of any kind, existential statements are all we have.  We want to give primacy to (or start with) individual observational experiences, and build our larger theories from on that foundation.  It seems like a good foundation: I, for one, cannot really doubt that I have observational experiences of a certain character.

Yet, all such experiences are singular events, referring to a limited class of objects. As such, they must be translated into existential and not universal logical sentences.  But these are just two different kinds of statements, and as such universal statements do not entail existential ones, and neither do existential statements entail universal ones.

Nick doesn’t take a stand with respect to the problem, he more enjoys the problems it creates for empiricists. Since Thomists are empiricists too, it’s certainly a problem we have to deal with. If you want the short answer, skip to the last paragraph.

For a longer answer, it helps to start with a point of agreement about universals. Despite all the differences in opinion about them, all sides agree that universals are not given in experience. The differences between the various schools arise from the various ways of diverging from this common point of departure.  Plato took the absence of universals in experience as proof that the things we experience participate in some world outside of experience which we knew from our previous life; Hume and Berkeley took this absence as proof that there simply were no universals, even in thought; and Aristotle’s position (at least as St. Thomas develops it) is that the universal is a certain way of understanding things as opposed to a thing understood. This says nothing about the question Russell raises, and if anything it appears to give some confirmation to is point of view,  since if all the doctrines about universals admit that they are not given in the things we experience it makes sense to question how in the world can we relate universality to experience. We only set out these various doctrines because they help us narrow the field of possible responses.  Since this started as a problem for empiricists, there is no reason to consider Plato’s response; and since it takes no effort to understand the response given by Humean Empiricists (who simply deny the existence of universals altogether, even in thought), the only response that needs to be explained is St. Thomas’s. Here’s what I think he would say:

There is a between what is known and the way it is known. For example, one and the same sense object can be known by different sense powers, whether we consider our own different sense powers (sight and touch) or our powers compared with different animals (our sight vs. a bat’s echolocation or a pit vipers infrared detection.) Just as sensation has its own way of knowing that is to be distinguished from the thing known, so does intellect (whether this happens because intellect just is a sort of sensation, or because it is analogous to it is not important at the moment.)  A universal results from, or simply is, a way that something is known. The experience of a universal seems to be nothing but this: when confronted with something in experience, you regard it in such a way that it is not distinguished from the members of some multitude. You walk into an office, say, and see the picture of a child on a desk. For you this is simply “a child” or “a memento” or something of the kind. You see the object as indifferent from any number of other similar things. None of the details much matter – any picture of any child would occasion the same experience as the one you are having now. But how different is the experience of the one who works in that office and at that desk! For him, the experience is certainly not of some generic memento, but of his own child, with all of his unique traits that divide him off from others. And so in one and the same thing experienced, we are capable of seeing the thing in the experience as distinguished or not distinguished from others. The first way of seeing it is the mode of considering a thing as a particular and the second is the mode of considering it as a universal. Each of these different modes of considering has its own unique benefit that the other lacks: the first mode of considering allows for interpersonal relationships, the power and force of art and history, and moral knowledge (since moral truth cannot abstract from particular circumstances); the second mode of considering allows for science and the teaching power of art. Nevertheless, both “universal” and “particular” here speak of modes of understanding not the thing understood.

We can, of course, say that the thing understood is a particular. If we do so, however, then this sense of “particular”  is distinguished from the mode of understanding, which means it is distinguished from both the universal and particular. In fact, it is false to say that our experience of things is particular, if we take this as the particular as opposed to the universal. We simply don’t experience every memento as showing us something uniquely set apart from every other memento. It takes a good deal of work to understand the particular in its particularity – only extremely prudent persons and great artists are capable of seeing the concrete particularity of situations well, and extremely prudent people and great artists are hard to come by. There is also a good deal of work in getting the universal exactly right. The vague universality that is oblivious to the distinction in things is also opposed to the reflective and critical universality that a scientist has.

And so to respond to Russell’s claim: what is existential or particular or singular can refer either to the thing understood, or the way of understanding. If the latter, it’s false to say that experience is particular; if the former, then the particular is no more opposed to the universal than it is to the particular.

Knowledge is the act of a knower

The act of the knower is to (a.) give rise to and (b.) be an indivisible reality

This reality is indivisible so far as it is not really divided into subject and object, but is rather is like a point from which a line drawn in one direction can be called the object, and drawn in another direction can be called the subject.

This undivided reality also serves as a point from which one development is physics, another psychology; one an aesthetic experience, another a painful memory, etc. Just as there is no limit on the number of lines that might arise from one point, there is no limit on the number of different experiences that might arise from the undivided reality that is and arises from the act of the knower. Science, art, logic, healing, religion, Naturalism, analysis, myth, etc. ad infinitum.

Within this indivisible point, there is a multitude that can be more or less reduced to unity or not. Say there is a dog in a room. A biologist walks in, and chooses to unify what he sees with other dogs, various wolves, even other various vertebrates. In each act, the very thing he sees is constituted by whatever unity is placed upon it. Now a child walks in and recognizes the dog as his own. His experience is not constituted by the sort of unity that the biologist gives to the experience. What is called universal is the sort of experience that has unity and relates to some multitude; particular is a unity that does not relate to some multitude. The experience itself, however, is indifferent to being taken as particular or universal. Both are simply lines of development that arise from the undivided reality.

The unity of a universal can be either definite or indefinite. Definite unity is called generic; indefinite unity is called transcendental.

In his essay Does Consciousness Exist? William James denies that there is some “stuff” out of which experience is made. What James affirms about consciousness is less interesting and less forceful, but his denial is a first-rate work of philosophy.

James’s case might be put like this: in experience there is some distinction between subject and object. What sort of distinction is it? The simplest explanation (the one that James will refute) is that it is the distinction between one thing and another. On this account, knowledge consists in the object being copied in the subject. If we wanted to show a picture of “what it is to experience a bowling pin” we’d make a circle for the subject, draw a bowling pin outside of it, and then draw a picture of a bowling pin inside the circle. The problem that immediately arises here is that the bowling pin outside of consciousness becomes superfluous to experience. We can certainly say that the object somehow causes or gives rise to the experience, but our whole picture of this makes it an extrinsic cause as opposed to something constituting the experience from within. James’s picture the same experience is this: draw a picture of a bowling pin, draw a line out from it to the left, and call it “the domain of the object”, and a line going to the right and call it “the domain of the subject”. In other words, one and the same thing is the limit of the subject and object. The distinction is therefore not one between one thing and another, but of two modes arising from the real indistinguishable unity of subject and object. In St. Thomas’s terms, knowledge is a mode of being another as other, and all being is a unity. To consider the thing in one way, certain properties are true of it and to consider it in another way other properties are true of it.  For example, when one looks around at one and the same room he is in, he can consider it either as the physical or the mental room:

The physical and the mental operations form curiously incompatible groups. As a room, the experience has occupied that spot and had that environment for thirty years. As your field of consciousness it may never have existed until now. As a room, attention will go on to discover endless new details in it. As your mental state merely, few new ones will emerge under attention’s eye. As a room, it will take an earthquake, or a gang of men, and in any case a certain amount of time, to destroy it. As your subjective state, the closing of your eyes, or any instantaneous play of your fancy will suffice. In the real world, fire will consume it. In your mind, you can let fire play over it without effect. As an outer object, you must pay so much a month to inhabit it. As an inner content, you may occupy it for any length of time rent-free. If, in short, you follow it in the mental direction, taking it along with events of personal biography solely, all sorts of things are true of it which are false, and false of it which are true if you treat it as a real thing experienced, follow it in the physical direction, and relate it to associates in the outer world.

This is the best articulation I’ve ever read of St. Thomas’s idea that the known is the act of the knower, and that knowledge is to be another as other. Thomists should take this image of knowing as a guiding star: the faculty of knowing or possible intellect is not some “stuff” out of which the exterior world makes mind things, but rather the power of giving rise to that which mediates and unifies different domains of being. The first model places a crude wall between subject and object, and ends up denying the very reality it sought to explain. A faithful submission to the data of experience removes the wall and divides the subject and object, as James says, in the way that we divide one point on a line, or a state border between two states.

From a commenter at Edward Feser’s site:

[E]veryone is conflating immateriality with subsistence. But that’s a mistake. According to St. Thomas, all souls are immaterial. (Cf. ST I, 75, 1) But, of course, not all souls are subsistent.

The argument is close enough to the texts to do what it needs to, but q. 75 a. 1 is not speaking to whether the soul is material, but whether it is an actual body, which is an easier question to answer and one about which there is far more agreement, since even Physicalists would agree that there is no evidence that soul is a body.

Few people are comfortable with using the word “soul” (this is true even of many theists, as the English translation of the mass makes clear) but if we take soul as whatever a living body has that a dead body doesn’t (where “has” is used in the broadest and vaguest possible sense) then the first theory about its nature we should consider is whether the physical body has a soul the way an engine has gas or a trebuchet has a counterweight; that is, we should consider whether the reason why the living being can do certain things is because there is some body within it that is lost at death. St. Thomas shows this is impossible since such an account is incoherent: the whole thing we are trying to explain is what makes the difference between one and the same body, and the soul-as-body account doesn’t do this at all.

What is interesting in this account is that it seems like exactly the sort of question that we contemporary people would want to solve with an experiment – and several quite good experiments have already been done long ago. We could weigh the body before and after death, or perhaps measure the volume it displaces. If we found a change, this would count as some sort of evidence for the soul-as-body hypothesis. This makes the question that St. Thomas is asking a good place to raise the question of the relative merits and downsides of the experimental method of discovering truths about the world and the (unnamed) approach that St. Thomas uses.