34. Motion, Change, and the Three Acts of the Intellect
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Lecture Notes
Main Topics #
The Four Kinds of Motion #
Berquist presents Aristotle’s classification of motion following the categories:
- Locomotion (change of place/ubi): movement from one location to another
- Alteration (change of quality): qualitative change in a substance
- Growth (change of quantity): increase or decrease in size
- Generation and Corruption (change of substance): coming to be and passing away
These are not found equally in all genera; rather, they follow the order of the categories themselves.
Hierarchical Ordering of Motion in Natural Philosophy #
The ordering differs from the categorical order:
- Locomotion is presupposed to alteration (things must be brought together spatially before they can change qualitatively)
- Alteration is presupposed to growth (food must be altered through chewing and digestion before it can become flesh and blood)
- Growth is the final stage
This ordering reflects causal dependency rather than logical order. Locomotion is the most known to us and seems to be the fundamental motion.
The Continuity of Motion #
Motion exhibits a quality of continuity. Locomotion (change of place) is the most clearly continuous form of motion, which is why other motions borrow their language from it. Berquist notes that this explains etymological connections: “coming to be” is derived from “coming” (change of place).
The Problem of Pre-Socratic Monism #
Early Greek philosophers (the atomists/mechanists) rejected all motion except locomotion. They argued that apparent qualitative changes (e.g., coffee becoming sweet when sugar is added) are merely unperceived changes of place of minute particles. The coffee remains bitter, the sugar remains sweet, but spatial rearrangement creates the illusion of qualitative change. Similarly, water becoming hot is merely faster molecular movement.
Thomas Aquinas addresses this by noting that the word “procession” (used in theology for the Trinity) is also borrowed from locomotion, demonstrating how our fundamental understanding of motion derives from spatial change.
Division of the Sciences Based on Motion #
The historical division into physics, chemistry, and biology reflects Aristotle’s classification of motion:
- Physics/Mechanics: Studies locomotion (change of place)
- Chemistry: Studies alteration (qualitative change)
- Biology: Studies growth (quantitative change in living things)
Berquist notes that this ordering was historically lost when atomic physics was classified with mechanics rather than with chemistry, despite Heisenberg correctly recognizing that atomic physics belongs with chemistry (alteration) rather than mechanics (locomotion).
The Three Acts of the Intellect #
First Act: Understanding What a Thing Is #
The first act is understanding the essence or quiddity of a thing. Examples:
- Understanding what a square is
- Understanding what a circle is
- Understanding what a dog is (though with less clarity than geometric forms)
Thomas notes that the first two acts are both forms of understanding (intelligere), though directed at different objects.
Second Act: Composition and Division / Understanding Truth and Falsehood #
The second act involves making judgments through:
- Composition (affirmation): asserting that predicates belong to a subject (“A square is a quadrilateral”)
- Division (negation): denying predicates of a subject (“A square is not a circle”)
Berquist proposes an alternative terminology: the second act is “understanding the true or the false” rather than merely “composition and division,” since understanding operates in both cases.
A crucial observation: in the second act, one seems to understand multiple things together (square and circle) in a way that cannot occur in the first act, where each essence must be understood through its own definition separately.
Third Act: Reasoning #
Reasoning involves:
- Putting together two or more statements (premises)
- Drawing a conclusion from them
- Understanding how the conclusion follows from the premises
In reasoning, one grasps three statements together while maintaining their order and unity. This is compared to an army: it remains one through its order, but loses its unity if the order breaks down.
The Unity and Progression of the Acts #
As one moves from the first act to the second act to the third act:
- The intellect seems to grasp together things that cannot be grasped separately in the first act
- The unity becomes more complex while maintaining coherence through order
- Each successive act involves understanding more entities in unified relation
The Linguistic Expression of the Acts #
Three Types of Speech (Locutiones) #
Each act of the intellect has a corresponding form of speech:
- Definition (for the first act): helps us understand what a thing is; lacks truth value in itself
- Proposition/Statement (for the second act): can be true or false; consists of at least two parts that signify separately
- Argument (for the third act): multiple propositions ordered toward a conclusion; the art of logic is said to be “the art of defining and reasoning”
The Nature of Names and Speech #
Berquist clarifies the distinction:
- Name (nomen): a vocal sound signifying by custom or convention, not by nature; no part of it signifies by itself (example: “Berquist” does not naturally mean “mountain-branch” despite etymological origins)
- Speech (locutio): has parts that signify something separately; conveys meaning through composition of parts
The Problem of Understanding Multiple Things Simultaneously #
Berquist raises a pedagogical puzzle: How can the intellect understand two different essences (like a square and circle) in the second act when it cannot understand them together in the first act?
The resolution:
- In the first act, one understands each thing through its definition, and these definitions are different. One cannot attend to both definitions simultaneously.
- In the second act, one understands a statement that has unity, even though it relates two different things. The statement itself has a single intelligible form.
- The second act involves understanding a judgment about the relation between things, not simply the things themselves.
Important Definitions #
First Act of the Intellect (πρώτη ἐνέργεια): Understanding the essence or quiddity of a thing; what a thing is (τί ἐστι).
Second Act of the Intellect: Compositio et divisio—composition (affirmation) and division (negation); understanding truth and falsehood through judgment.
Third Act of the Intellect: Reasoning (ratiocination) through arguments; drawing conclusions from premises.
Definition (definitio): Speech that helps us understand what a thing is; has parts that signify separately but expresses essence without truth value.
Proposition (propositio): A statement capable of being true or false; consists of subject and predicate in composition (affirmation) or division (negation).
Argument (argumentum): An ordered set of propositions (premises) from which a conclusion is drawn; the material of the third act of reason.
Examples & Illustrations #
The Coffee Example (Atomism) #
Marcus’s bitter coffee becomes sweet when sugar is added. The pre-Socratic atomists would say: there is no qualitative change, only imperceptible change of place. The sugar particles, too small to see, have mixed with the coffee. Both remain what they are; only their spatial arrangement has changed.
The Hot Water Example (Molecular Motion) #
Boiling water exhibits apparent qualitative change (cold to hot). The atomist response: the water molecules move faster and faster—again, only imperceptible locomotion, not true qualitative change.
Square and Circle #
Berquist uses geometric forms repeatedly to illustrate the distinction between the acts:
- Understanding “square” alone (first act)
- Understanding “a square is a quadrilateral” (second act: true composition)
- Understanding “a square is not a circle” (second act: true division)
- Understanding “a square is a circle” (second act: false composition)
Geometric Distinction #
A square and circle can be compared: one can circumscribe a square around a circle or a circle around a square, but this does not make them the same.
Student Recognition #
The example of recognizing a dog: Berquist notes that he usually recognizes a dog when he meets one, suggesting practical understanding of “dogness” even if not philosophical clarity.
The Cat in the Backyard #
Berquist mentions a cat in the backyard as a present example of understanding “catness” through immediate recognition rather than definition.
Questions Addressed #
Why Is Locomotion the Most Fundamental Motion? #
Answer: Locomotion is the motion most known to us because it is the most clearly continuous and observable. Other motions are understood by analogy to spatial movement. The presupposition of locomotion to alteration, and of alteration to growth, shows its foundational role.
How Can One Understand Two Different Things in the Second Act? #
Answer: In the second act, one understands a unified statement that relates two things, not the things separately. The judgment itself has unity through composition or division, allowing simultaneous understanding of both terms within the propositional form.
What Is the Difference Between a Definition and a Proposition? #
Answer: A definition (first act) aims at understanding what a thing is and does not possess truth value in itself. A proposition (second act) asserts something about things and can be true or false. Definitions are components of propositions but are not themselves true or false.
How Do Words Derive from Motion? #
Answer: The word “to come to be” (becoming) is etymologically derived from “coming” (locomotion). This is because locomotion is the most evident and known form of motion, so we borrow language from it to describe other changes, even in theology (e.g., “procession” in discussions of the Trinity).
Notable Quotes #
“Change of place is presupposed to alteration, right? And then you have to alter the food, right? By chewing it and digesting it, right? Before you can make flesh and blood and bone out of it, right?” — Duane Berquist
“Locomotion, of course, is the kind of motion that’s most known to us.” — Duane Berquist
“The first meaning of a word equivocal by reason, right? Tends to be not only something sensible, but more precisely something… continuous or in the continuous, right? Well, change of place is more clearly continuous than change of… quality.” — Duane Berquist (summarizing Thomas Aquinas on Aristotle)
“The first two acts are both a kind of understanding, right?” — Duane Berquist (on Thomas Aquinas’s view)
“I sometimes like to call the second act as understanding what? Understanding the true or the false.” — Duane Berquist
“It’s kind of interesting, huh? In the second act, I might come up with this instinct that a square is not a circle. And could I understand that a square is not a circle unless at the same time I understand a square and a circle?” — Duane Berquist