Know Thyself: How the Understanding Soul Knows Itself Through Its Act (Summa I, Q.87, a.1), with Descartes, and Why the Indistinct Is More Certain

Orientation #

He opens by placing the question: having treated how the soul knows what is below it, we are now “up to the question on how the soul knows… itself, and the things that are in it”; the next question will be knowing the things above it, then the knowledge of the separated soul. Verified sources: the class reads ST I q. 87 a. 1 and draws on the handout for Physics I (Thomas, lectio 13). The previous class finished q. 86 on singulars, contingents and future things and announced this question; the next takes a. 2 on knowing habits.

The class, in order #

1. The four articles and “know thyself” (“Know thyself. Okay, so I say, to whom is that addressed”) #

The point: the prologue to q. 87 lists four questions, and he uses the Delphic exhortation to show why the first is a question at all.

• The four: (1) whether the soul knows itself through its essence, which “incidentally is the way the angels know themselves, and the way God knows Himself”; (2) how it knows the habits in it; (3) how it knows its own act (I understand a triangle, know that I understand, know that I know that…); (4) how it knows the act of the will (I know I love candy, food, wisdom).
• Seven wise men at Delphi, “know thyself”: addressed to one who can know himself but doesn’t, hence not to angels or God (they know themselves), not to beasts (they can’t), but to man; more specially to the soul (the soul can know what a soul is, the body cannot know what a body is); most specially to reason, “the only part of your soul that can know itself.” Plato’s Parmenides takes more liberties, applying it even to knowledge of knowledge.
• Aside on a. 4: some say you cannot know that you love God, only conjecture it, quoting “a man doesn’t know whether he be worthy of love or hate”; a particular question Thomas takes up sometimes.

2. Objections and sed contra (“investigate the soul through its powers”) #

The point: the three objections argue from Augustine, from the angel, and from Aristotle; the sed contra from Aristotle.

• Obj. 1: Augustine, De Trinitate IX: the mind knows itself through itself because it is bodyless.
• Obj. 2: angel and human soul share the genus of understanding substance; the angel understands itself through its nature; so does the soul.
• Obj. 3: in things without matter, the understanding and the understood are the same (De Anima III).
• His gloss on obj. 3: Aristotle knew this of angels and God, “but he didn’t think that our soul knew itself through itself”: you investigate the soul through its powers, the powers through their acts, the acts through their objects; we know our soul “not through itself but through other things.”
• Sed contra (De Anima III): the understanding understands itself as it understands other things, i.e. through likenesses, not essences.

3. Corpus: knowable as it is in act (“do you know any ability?”) #

The point: each thing is knowable according as it is in act, not in ability (Metaphysics IX, the book on act and ability).

1. You know an ability only through its act: how do you know I can walk or talk? If I’m not walking or talking, “for all you know, I might be mute or crippled.”
2. Hence (Heisenberg and Aristotle) we know matter, which is ability for form, only through the forms it takes on; sight does not perceive the coloured-in-ability but only the coloured-in-act.
3. First matter, pure ability for substance, is known only by its relation to form (Physics I): first matter is to man and dog as clay to sphere and cube. Clay can be sphere or cube, not both at once; being a sphere it keeps the ability to be a cube, but becoming a cube ceases to be a sphere. So first matter, when it is a man, retains the ability to be a dog, and the reverse. Eating, and being eaten, show “how true this is”: something in me able to be a dog, a lion, worms, dust.
4. So God, pure act, is most knowable in himself; but (beginning of the Physics) the most knowable is least knowable to us because of the weakness of our mind, which “the second book of Wisdom” [ed.: Metaphysics II] calls the chief difficulty in knowing, though some things are hard to know because they are hardly actual.

4. God and the angels: cause, effect, and a common cause (“God doesn’t get his knowledge from things”) #

The point: among immaterial substances, as each is act by its essence, so it is understandable through its essence; God perfectly, the angel not completely.

• God, pure act, through his essence understands himself and all other things: knowing the cause perfectly he knows every effect, and everything is his effect. He does not reason from himself to things as we do. Student: “All things get their existence from God’s knowledge.” Yes.
• Thomas’s threefold distinction: knowing is by likeness, and a thing is like another (a) as its cause, (b) as its effect, (c) because a third thing causes both. God’s knowing: he is cause of everything. Ours: the reverse, an effect of things acting on sense and mind. The angel in between: God infuses thoughts into the angels; the likeness between things and angelic thoughts is because both are effects of God.
• Plato’s forms resemble this: material things partake of the forms and we partake of the forms, so we know things. “That’s really not the way we are… that’s the way the angels are.” The angel is created with his natural understanding completely formed. Marcus, when little: “Why can’t we be born knowing everything?” — “You ought to be an angel.”
• The angel’s essence is act in the genus of understandables but not pure act, since his substance and existence are not the same as in God, “I am who am.” So his understanding is not completed by his nature: he knows himself through his essence but not everything else through it; he needs added forms, given at creation, because his essence is not infinite, not a likeness of everything.
• Aside: he once told [name unclear in recording] he wanted to study the angels; the reply: “Any time, but you’ve got to understand your own soul first.”

5. Our understanding: prime matter among understandables (“we’re way down to the bottom”) #

The point: the human understanding is in the genus of understandables as a being in ability only, as first matter is in the genus of sensibles; hence “possible understanding” (intellectus possibilis; with intellectus agens).

• Considered in its essence it is understanding only in ability: from itself it can understand but cannot be understood except as it comes to be in act.
• The Platonists set an order of understandables above understandings, the partaker below what it partakes of; if our understanding were actuated by partaking of separated forms, it would understand itself through those bodyless things.
• But it is connatural to our understanding in this life to turn to material and sensible things: the proper object of reason is “what it is” of something sensed or imagined; what cannot be sensed or imagined we understand by likeness or by negation (God incorporeal, angels separated from matter).
• So it understands itself as it comes to be in act through forms abstracted from sensibles by the light of the agent understanding, the act of those understandables and, through them, of the possible understanding: “not through its own nature, but through its own act.” I am the ability to understand, known through the act of understanding. Shakespeare’s definition of reason: “the ability for large discourse, looking before and after.”

6. Two ways of self-knowledge; the brain and the object (“whether the brain is to the universal understanding as organ”) #

The point: self-knowledge happens in particular (Socrates perceives he has an understanding soul because he perceives himself to understand) and in universal (the nature of the human mind considered from the act of understanding).

• I know I have an understanding soul, not just a sensing soul like cats or a living soul like plants, since “I understand at least what a triangle is.”
• The judgment and efficacy of this knowledge belong to us as the light of our understanding derives from the divine truth in which the reasons of all things are contained; Augustine, Trin. IX: we look upon an inviolable truth and define not what sort each man’s mind is but how it ought to be. His caution: Augustine says we see truth in the eternal reasons, but “it’s really… in our natural understanding, which is a likeness of the eternal truths; we’re not seeing it in God.” Augustine’s words sometimes give that impression.
• The distinction: knowing that I understand vs. knowing what the nature of understanding is. The man in the street knows he understands but may think his brain is his reason; many natural scientists and psychologists think so.
• The brain-blow argument (blow, alcohol, drugs interfere with thinking, therefore the brain is the organ of thought): it shows a connection, but not whether the brain stands to universal reason as organ or as object. Object of reason: what-it-is of something sensed or imagined; to understand triangle again I form an image of a singular triangle and understand the what-it-is of that. Analogy: I see the blackness of your robes; if you leave the room that interferes with my seeing, but on the side of the object, not the organ (colour, sound of the telephone, smell of the wine in the glass are all “out there”).
• Separate argument that universal reason is not a body: a likeness received universally cannot be in the continuous, since any triangle in the continuous is here or there, hence singular; what is received in quantity is individualized. So the interference must be on the side of the object, and we then see why injuring the brain interferes with thinking.

7. Descartes: certitude is not clarity (“the confused is more known to us than the distinct”) #

The point: “I think, therefore I am” gives certainty that I think, not distinct knowledge of what thinking is; Descartes’ “tremendous mistake” was to couple certitude with clarity and distinctness.

• Cause of the mistake: influence of mathematics, more certain and more clear and distinct, so he concluded the two go together. Logically this is a third-figure enthymeme, Aristotle’s example: Socrates is just, Socrates is a philosopher, therefore philosophers are just; his own: Berquist is half Swedish, Berquist is a philosopher, therefore philosophers are Swedish. “A very weak argument.” Descartes “said we don’t need logic.”
• Aristotle’s argument is a first-figure syllogism: the confused is more known to us; what is more known to us we are more certain of; therefore the confused is more certain for us.
• Equivocation of “confused”: mistaken (thinking a dog is a cat, “mixed up”) vs. indistinct (“a dog is an animal” does not distinguish dog from cat, but is not mistaken). Aristotle means simply the indistinct.
• Examples of precision lowering certainty: dry red wine vs. Cabernet Sauvignon vs. California/Australia/France; his age (over 20? over 60? sure; exact age, less sure) vs. “between fifty and a hundred”; his weight this morning (guesses 176, 190; actual 166.8; “the wrong decade”); a birth certificate is not always correct: records gave his father’s birth as 1891 and 1892, so one is surer of “the 1890s”; two walls: surer one is longer than that it is seven feet three inches longer, and even measured it may be 7'3" and a tenth, so the precise figure is strictly mistaken while “longer” is not; weighing machines differ (college dance anecdote: pulling on the machine so the girls weighed more).
• Two consequent mistakes: (a) what one is very sure of one must know clearly and distinctly (cogito); (b) what is clear and distinct must be true. Note Thomas’s distinction here: both knowledges come through the act, but the second needs the long investigation “as we did” (immateriality, etc.).
• Against (b): de Broglie, “contrary to Descartes, nothing is more misleading than a clear and distinct idea.” Clarity in science comes by idealization: rounding lab numbers to fit equations within an acceptable margin of error, going into the imagination out of reality. Einstein’s first example: the law of inertia, a body without external forces, “not one example in our experience.” Heisenberg: idealization loses “the immediate connection with reality”; on Aristotle’s critique of the Pythagoreans forcing facts to theory, Heisenberg says you must force the facts, otherwise science is impossible; in his Gifford lectures, the vaguely defined concepts of natural language have greater stability in the expansion of knowledge than the precise terms of science, “back to Aristotle’s position.”

8. Presence vs. investigation; Augustine, Trin. X (“a diligent and subtle inquisition”) #

The point: for the first knowledge the mere presence of the mind suffices, the source of the act in which it perceives itself, hence “knows itself through its presence”; for the second, presence does not suffice but a diligent, subtle investigation is required.

• So many are ignorant of the soul’s nature and many have erred; they think the understanding is the brain. After Einstein died they preserved his brain.
• Augustine, Trin. X: the mind seeks itself not as something absent but to discern what is present, i.e. its difference from other things, which is to know what it is.
• The seven wise men named: Thales, Solon, Pittacus, Periander, Bias of Priene (“most men are bad”, praised by Heraclitus; “it’s true though”). Their exhortation applies to man, soul, and reason, and requires investigation at every level.

9. Reply to obj. 1: through itself, but through its act (“because it loves itself”) #

The point: the mind is said to know itself through itself because it finally arrives at knowledge of itself, though through its act; not as if it were the form by which it understands itself.

• The subjoined “because it loves itself” belongs to the image of the Trinity: when reason understands itself, a thought of itself proceeds, and knowing itself it begins to love itself, as the Son proceeds as Word and the Spirit as love.
• “Known to itself” in two ways: (a) not through another, as first principles; (b) not per accidens, as colour is per se visible and substance per accidens; back to the two kinds of per se against per accidens.
• Asides: Thomas “piously expounds” Augustine where his speech goes too far (one may say God from God, light from light, but not divine nature from divine nature, though God and his nature are the same; the way of signifying differs). Augustine, trained in rhetorical schools, had “tremendous natural ability”; with Aristotle (and Dionysius) the major influence on Thomas; Lombard’s Sentences and the Catechism lean on Augustine. Student: Augustine harder to read, less ordered — he agrees: more rhetorical, lends itself to misunderstanding, but beautiful in Latin (“ubi amat quam ubi animat”, the soul is more where it loves than where it animates). Father Boulet’s Augustine letter: no opposition of faith and reason, since we are capable of faith because we have reason. Thomas’s commentary on John draws on Chrysostom and Augustine on almost every passage (Pius XII: no follower of Thomas without it); the anecdote of Thomas preferring Chrysostom’s homilies to being master of Paris. Augustine (John 8, Confessions): knowledge is a common good; being attached to a truth because you found it is loving it “because it’s mine, not because it’s true,” and “you’re driven from that to err” (his own piddling geometrical theorem beside Euclid).

10. Reply to obj. 2: the angel is act, we are ability (“who most stupidly taught”) #

The point: the angel’s essence is act in the genus of understandables, so it is both understanding and understood; the human understanding is entirely in ability toward understandables, like the possible understanding, or is the act of understandables abstracted from images.

• Student: the soul in the body is not wholly separated from matter, so it is that which understands; once separated, will it be actually understandable like the angels? He thinks so, “but we have to wait to see what Thomas says.” (He notes he had misread which objection was which; obj. 2 is the angel objection.)
• Our understanding is the lowest possible understanding as prime matter is the least actual. David of Dinant taught God is first matter; Thomas: “most stupidly taught,” not gratuitous insult, since nothing is further from pure act than pure ability; “God is a stone” would be closer. Paraphrase: Alfarabi most stupidly taught the human mind is the divine mind; “an angelic mind” would be closer.

11. Reply to obj. 3: understood in act, and separated substances (“in a way I become a triangle”) #

The point: Aristotle’s dictum is universally true of every understanding: as sense in act is the sensible in act by the likeness that is its form, so understanding in act is the understood in act by the likeness of the thing understood.

• The definition of triangle in my mind contains the nature of triangle, so “in a way I become a triangle” — but not really, since I have that nature in a different way. So the human understanding, actuated by the form of the thing understood, is understood through that same form as through its own.
• Second way of solving: “without matter” = “understood in act”. The difference: some essences are without matter — the separated substances (the philosophers’ name; “angel” is the Bible’s, from their being sent as messengers; the name is not in Aristotle), each both understood and understanding; others’ essences are in matter and only their likenesses abstracted. The Commentator (De Anima III): the statement holds only in separated substances.
• So the angel, joined to a substance wholly separated from matter, understands it through itself; our soul, the first act of a natural body, is not fully understandable while in the body. The separated soul: “one of the articles coming up later on.” Break.

His words #

• ability — his rendering throughout [ed.: potency]; “act and ability” for Metaphysics IX.
• possible understanding / potential understanding — intellectus possibilis; with intellectus agens, the “agent understanding, the acting upon understanding.”
• understanding — for intellect; “understanding substance”, “understandables.”
• the what it is of something sensed or imagined — the proper object of reason.
• Wisdom, second book — [ed.: Metaphysics II].
• confused — indistinct, not mistaken; “vaguely defined” in Heisenberg.
• third figure enthymeme — his classification of Descartes’ argument.
• idealization — rounding lab numbers to fit equations, in the imagination.
• known through its presence — the first self-knowledge.
• separated substances — the philosophers’ name for the angels.
• most stupidly taught — Thomas on David of Dinant, extended to Alfarabi.

Texts #

Read in class

• Thomas Aquinas, ST I, q. 87, prologue and a. 1 (objections, sed contra, corpus, replies), translated and commented.
• Aristotle, Physics I via Thomas’s commentary (lectio 13, per verified sources; handout): first matter to man and dog as clay to sphere and cube; the confused more known to us.
• Augustine, De Trinitate IX and X, as quoted in the article.

Mentioned

• Aristotle, De Anima III; Metaphysics IX; Metaphysics II (“second book of Wisdom”); Prior Analytics/Rhetoric example of the third-figure enthymeme (inferred).
• Plato, Parmenides.
• Shakespeare, “large discourse, looking before and after.”
• Descartes, “I think, therefore I am.”
• de Broglie on clear and distinct ideas; Einstein on the law of inertia; Heisenberg, Gifford lectures, on Aristotle and the Pythagoreans.
• Averroes (“the Commentator”), De Anima III.
• Peter Lombard, Sentences; Catechism of the Catholic Church; Thomas, commentary on John; Chrysostom’s homilies; Augustine, Confessions, homilies on John (ch. 8).
• David of Dinant; Alfarabi.

His questions #

• “Know thyself” — to whom is that addressed? To one who can know himself but doesn’t: man, more specially the soul, most specially reason.
• Do you know any ability? How do you know I have the ability to walk or talk? Only through the act; not walking or talking, I might be mute or crippled.
• Why does God know all things by knowing himself? Knowing the cause perfectly he knows every effect, and everything is his effect.
• Does a blow on the brain interfering with thought show the brain is the organ of thought? It shows a connection, but not whether on the side of organ or object; a separate argument shows it is object.
• Is “Socrates is just, Socrates is a philosopher, therefore philosophers are just” a strong argument? No; a third-figure enthymeme, Descartes’ only backing.
• Which of these walls is longer, and how much longer? Surer that it is longer than that it is 7'3" longer; the precise figure may be strictly wrong.
• Is a birth certificate always correct? No: his father’s records gave 1891 and 1892.
• Once the soul is separated from the body, will it understand itself like the angels? He thinks so, but “we have to wait to see what Thomas says” — left open.