Summa Theologiae I, Q.79, A.5: Is the Agent Intellect One in All Men?

Orientation #

He opens by placing the class: “we’re up to the fifth article here in question seventy-nine,” and the body of the article draws on “the previous article” where the agent intellect was shown to be a power of the soul. A sentence before the prayer is the tail of last time’s remark on a verse where the author wants his readers “to believe and to hope and to love” (prev. lecture). The neighbouring classes treat Thomas on the agent intellect (q. 79) with James 1 before, and the De anima commentary and memory after.

The class, in order #

1. The order of the first four articles (“the questions are reversed in the order”) #

Point: articles 1–4 of q. 79 are paired but not in parallel order. Art. 1 asks whether the (possible) understanding is a power of the soul; art. 2 its nature (an undergoing power); art. 3 whether there is an agent intellect at all; art. 4, the counterpart of art. 1, whether it is something of the soul. He leaves the reason “to you,” but suggests: for the agent intellect the very existence is in question (art. 3 first), because most people know they can understand and reason and can choose, but are unaware of this third power that makes what is in the images actually understandable.

2. Objection 1: what is separated is not multiplied (“nothing that is separated from the body”) #

Reading: what is separated from body is not multiplied with bodies; the agent intellect is separated (De anima III); so it is one in all. He notes this touches the same question as how there can be many souls once they exist apart from the body, and says we will see whether Thomas solves it “partly along those same lines.”

3. Objection 2: the cause of unity is more one (“more something one”) #

Reading: the agent intellect makes the universal, one in many; what causes unity is more one; so it is one in all. The principle behind it: when the same is said of two things, but of one because of the other, it belongs more to the cause — as sugar making coffee sweet must itself be sweet. His diagnosis: the objector plays on senses of “one.” Heraclitus’ fragment (“listen not to me but to reason: all things are one”) could mean stupidly that dog, cat and tree are one thing; or that each thing is in itself unified (in wisdom one is a property of being: whatever is is simple or composed, the composed is not unless its parts are unified, so a fortiori the simple is one); or that the universe has a unity of order, of origin and of end. So your agent intellect and mine may be “one” as each making something one out of many images, without being numerically one — like the bad argument “we understand the same things, so we have one understanding.” Ways of speaking that suggest one where there are two: “return your love” (not handing back the same love, though it has a likeness to justice, where I give back what you gave); Romeo and Juliet’s prologue, “a pair of star-crossed lovers take their life” — life in the singular; The Phoenix and the Turtle, where two become one and love has “murdered number.” “Gotta watch some of those ways of speaking.”

4. Objection 3: all men agree in the first concepts (“a whole is more than a part”) #

Reading: all men agree in the first thoughts of the understanding, which are known through the agent intellect; so all share one agent intellect. Example: nobody denies the whole is more than the part — pay him part of his salary, serve part of the meal, deliver part of the car, and he will “scream and rave,” showing what he thinks. Aside: Bertrand Russell, “the sophist,” denied it, and De Koninck refuted his argument. He grants such agreement is rare among men: his widowed mother and aunt could not set up house together (sisters do things differently); Warren Murray: would two of us ever teach the same course the same way?; Father Fortier at Assumption: nobody can teach somebody else’s course. By contrast, Father, Son and Holy Spirit have literally one mind; the early Church had “one heart, one soul” — “unanimous” means one soul, yet it is not really one soul; it is a way of speaking.

5. Sed contra: light is not the same in the things lit (“not the same light in diverse things”) #

The agent intellect is like a light (De anima III), and the same light is not in diverse illuminated things; so not the same agent intellect in diverse men.

6. Body: it depends on what went before (“depends upon the things that have gone before”) #

Argument:

1. If the agent intellect were not something of the soul but a separated substance (angel, God), there would be one for all men — as one sun enables all eyes to see. This is what those who posit one agent intellect understand.
2. But art. 4 showed it is a power of the soul.
3. There cannot be one and the same power in number of diverse substances (the “non enim potest” sentence). Conclusion: there are many agent intellects, multiplied with souls, which are multiplied with men. Student: how does the last sentence fit? Answer: it is a premise supplied alongside the “si autem intellectus… " conditional, needed to draw the conclusion; the power of my soul cannot be the power of yours, however alike.

7. Reply to objection 1: two senses of “separated” (“not the act of some bodily organ”) #

Aristotle proves the agent intellect separated through the possible intellect being separated. Recalled reason from De anima III: the possible understanding receives the natures of all material things, as the eye receives all colours and could not if its fluid were coloured, and the tongue could not taste all tastes if it were itself sweet; each sense lacks its object, so the possible understanding lacks all material nature (“other reasons you can give besides that”). Then, since its proper object is what is sensed or imagined, which is not actually understandable, the agent intellect is needed; what makes material things actually immaterial must a fortiori be immaterial, and the agent is more perfect than what it acts on. So “separated” means: a power of the soul but not in a body, not the act of a bodily organ — not a separated substance in the Greeks’ sense (angels in philosophy are “separated substances,” immaterial substances). Reasoning is from one being immaterial/separated to the other being so. Aside: he begins the Father Boulay dinner story at Laval; the recording ends before it.

His words #

• “undergoing power” — the possible understanding as receptive [ed.: passive power]
• “acting upon understanding” / “active understanding” — his rendering of intellectus agens
• “make understandable and act what is in the images” — the work of the agent intellect [ed.: to make the phantasms actually intelligible]
• “one is kind of like a property of being” — whatever is is one
• “separated substance” — Greek term for an immaterial substance by itself; angels
• “separated” (of a power) — not the act of a bodily organ
• “a fortiori” — his phrasing of the step from possible to agent

Texts #

Read in class

• Thomas Aquinas, Summa theologiae I, q. 79, a. 5: objections 1–3, sed contra, body, reply to obj. 1 (verified) Mentioned
• Summa theologiae I, q. 79, aa. 1–4 (order of the articles; art. 4 as premise)
• Aristotle, De anima III (agent intellect separated; like a light; possible intellect receives all natures)
• Heraclitus, fragment on all things being one
• Shakespeare, Romeo and Juliet, prologue; The Phoenix and the Turtle
• Scripture, the early Church of “one heart, one soul” (Acts, inferred)
• Bertrand Russell on whole and part; De Koninck’s refutation

His questions #

• Why is the order of articles 1–4 reversed? Left to the students; his suggestion: the existence of the agent intellect is what people don’t recognise.
• Does “cause of unity is more one” make my and your agent intellect numerically one? No; “one” has many senses, so each may be one in itself without being the same one.
• Is “returning your love” giving back the same love? No, though the phrase has a likeness to justice; a way of speaking.
• Anybody here doesn’t know a whole is more than a part? Nobody; whoever says so betrays it when shortchanged.
• Is it really one soul the early Church had? No; a way of speaking, unlike the Trinity’s literally one mind.
• How does “non enim potest…” fit the argument? It is a premise joined to the “if a power of the soul” conditional.
• Why is the possible understanding not a body? It receives the natures of all material things, as eye and tongue lack their objects.