Motion as the Act of the Able, and Place: The First Senses of 'In'

Orientation #

He says they are in “the second reading” and will start again “from the beginning, so we won’t be caught up with what we saw last time” (prev. lecture: the definition of motion). He announces the plan: from motion they will go to time, skipping place, but he will “say a few things about place” and the word “in”; Book VI (the infinite in every motion) is to be looked at later.

The class, in order #

1. Act and ability divide each genus (“Having divided act and ability according to each genus”) #

The point: act and ability are not an eleventh category but crisscross the ten genera, dividing each.

• Examples per category: able to be a substance vs. actually this substance; able to be five foot ten vs. actually five foot ten; able to be hot vs. actually hot; able to be a grandfather vs. actually one.
• God is put in no genus (that would limit Him), yet is spoken of as pure act; so act/ability is “of even greater universality” than the ten genera.
• Plato in the Sophist gives a kind of definition of being: what can act upon something or be acted upon. Aristotle makes act/ability a main division of being, with a whole book on it, the ninth book of Wisdom [ed.: Metaphysics IX].
• The definition “the act of the able to be, as such” has three parts: (1) act, the genus; (2) of the able to be; (3) as such.
• Motion translates kinesis; English “motion” narrows to change of place, but he means alteration (change of quality, “act of the alterable”), growing (act of the growable), decreasing, generation of the generable, corruption of the corruptible, and in general motion of the movable.
• Why not define motion as “act of the movable”? That would define motion by itself. True statement, not a definition.
• Aside: “I guess you get to be my age to start shrinking, they say.”

2. Manifesting the definition; moved movers (“the natural mover is movable”) #

The point: Aristotle manifests that motion is the act of an ability, and that the movers we know first are themselves moved.

• Buildable: the word is taken from “able”, names an ability; being built is plainly an act of that ability. Same for learning, rolling, growing, ripening, aging.
• Some things are both in ability and in act, not at once or according to the same: actually hot but able to be cold, and vice versa. So many things act upon and undergo from each other; reminds him of Newton, “for every action there’s a reaction.”
• Everything acts upon another insofar as it is in act, and is acted upon insofar as it is in ability — the famous statement that every agent acts insofar as it is in act.
• “Natural mover”: nature was defined as beginning and cause of motion and rest in that in which it is first, as such, not by happening; so a natural mover is one subject to motion itself, moved while moving. These moved movers are most known to us; hence “it seems to some that every mover is moved.”
• Books VII and VIII of Natural Hearing [ed.: Physics] will reason to an unmoved mover; Aristotle here only hints (“it will be clear from other things”). He recalls that James (after hesitating between James and Jude; the class says James) says there is no shadow of change in God.

3. “As such”: bronze, healthy and sick, sphere and cube (“bronze is able to be a statue”) #

The point: motion is not the act a thing already has but the act of its ability, and the abilities must be distinguished by what they are abilities for.

• Bronze is able to be a statue, but motion is not the act of the bronze as bronze; if to be bronze and to be in ability were the same by definition, the act of bronze as bronze would be motion. The act whereby it is actually bronze is not its motion.
• Contraries: the ability to be healthy and the ability to be sick are “other” — but he warns, “I’ve got to be careful about this.” Are they two abilities as walking and talking are? A student suggests sickness is a negative. His test: I can walk and talk at the same time, but not be healthy and sick at the same time; so if they were two abilities in that way, I could be both. In a way they are the same ability, yet not defined the same way.
• Clay: able to be a sphere and able to be a cube (cannot become both at once, so in some way one ability) vs. able to be a sphere and able to be cold (different abilities: can become both at once). Becoming a sphere is an act of its ability to be a sphere, not of its ability to be a cube; becoming healthy is an act of the ability to be healthy, not to be sick. That is what “qua”/“as such” brings out.
• If they were simply the same ability, sick and healthy would be the same thing; but the subject able to be healthy and sick — “moisture or blood or wherever it is” — is one and the same, just as neither colour nor visible are the same. Hence the act of the able as able is motion.
• His addition (fuller when Aristotle repeats the definition in the eleventh book of Wisdom [ed.: Metaphysics XI]): to separate motion from every other act the third part must be understood to include (a) imperfectness — the act of what is able insofar as it is still able, not yet fully actualized (student’s suggestion); (b) order per se to a further act (student’s suggestion): if not on the way to something further, not motion.
• Hall/room example: out in the hall I am actually a man and actually a philosopher but only able to be in the room. Coming into the room is not the act whereby I am a man or a philosopher; it is the act of me insofar as able to be in the room; and not the complete act (my being in the room, as now) — so neither pure ability nor pure act, “something in between.”
• Objection: the man standing in the doorway has partly actualized his ability to be in the room; is standing motion? That would be a contradiction. Reply: it is accidental to standing in the doorway that you ever come in more — e.g. standing there to check credentials as at the airport, not invited to the party. But as long as I am coming through the doorway I am going to be in more; so motion is an act of this ability on the way to a further act of the same ability. “So maybe you have to understand all three of those things finally in the last part of the definition.”

4. Students’ questions on lack and on coming to be (“does the able to be include lack”) #

• Does “able to be” include lack? He is cautious: motion is certainly an imperfect act and lack is certainly involved, but he would not put lack in the definition strictly speaking.
• Student: once I am in the room I am no longer able to be in the room — semantics? He: the point is that motion is not the act of the actual; the act of the actual is “more what we call form… or being, if you wish.”
• Student: could one define motion by first defining coming to be (not necessarily motion), so motion is the act of what is able to come to be, insofar as still able? He tries to locate the question (becoming between contradictories? a becoming that is all at once?) — a becoming all at once would be something different from what is defined here. “Let’s wait on that… that’s more difficult.” Left open.

5. Digression on place: against place as dimensions (“what would lead us to distinguish between the place of a body”) #

The point: the common modern view of place as the dimensions a body occupies is questionable; Aristotle’s view is that place is the inner surface of the containing body.

• Order of the books: Book III’s second part is the infinite, more fully treated in the books on the universe (De Caelo et Mundo); the infinity in every motion is taken up in Book VI; Book IV takes place first, then time. They will not read place, but he will not “leave you entirely ignorant.”
• What leads us to distinguish place from body: locomotion — one body leaves a place, another comes into the same place; without change of place we probably would not distinguish them.
• Common view (modern science, using “space” for place; from Newton, infinite space in every direction): place is the dimensions a body occupies, roughly equal to the body, staying there when the body leaves. Student offers “location”, “where”; he: locus is the word for place, but “where” is the interrogatory, and to be where is to be in place (“I am in this room, in Peterstown”). Student worry: then a smaller body could be only in part of the place, and there was no place before the body. Another student: perhaps only length and width, an x-y coordinate.
• Two difficulties:
  1. What are those dimensions? A body is defined as what has length, width and depth; if something with those is there, you have another body, “very fine and subtle,” and two bodies interpenetrating. If nothing is there, how can nothing have length, width and depth? (Empedocles, read earlier, denies the empty; the empty is nothing unless something is there, and then it is not empty.)
  2. Even granting the dimensions are real, why say the body is in the place rather than the place in the body, since they coincide? Euclid’s first theorem: two circles drawn on a line, parts coincide — arbitrary to say one is inside the other, even if you imagine one pulled away. Student: the body leaves the place but the place does not leave the body; he: not a good reason for “in”. Student: the parking-lot place is a location on another body, the earth, and must be big enough for the car; he: that treats place and body as equal and coinciding, so why “in” (the first meaning of “in” is being in place, a student notes).
• Aristotle’s view: place is like a jar or vase — not the inner dimensions of the glass but its inner surface, together with the outer surface of the liquid. Fill the glass with water, pour it out, fill it with wine, beer or milk. Now “in” makes sense: the water is contained by the inner surface of the glass, not the glass by the water. Here a real distinction is available: the outer surface of the water and the inner surface of the glass are together but not the same surface; place is the inner surface of the containing body. This fits “our original confused insight that bodies are in place,” not with place.
• Aristotle adds an order to the whole universe: the post in the river — the water flowing around it, as Heraclitus said, is always different water, so the inner surface of the containing water belongs to ever-different water; yet the post does not change place, because whatever water it is, that inner surface has the same relation to the shores. Something immobile about the inner surface, though not the same body.
• Student: on the dimension theory place ends up existing only in the mind; he agrees — this is what Kant does eventually, and Einstein rejects Newton’s space as a figment; but the imagination easily goes that way.
• Aside: he once proposed a second philosophy-of-nature course named “Motion, Place, Time”; it came out on the schedule as “Space, Time, Motion” — “somebody just did it without thinking.”

6. The eight senses of “in” and Thomas’s ordering (“eight different senses of the word in”) #

The point: Aristotle distinguishes eight senses of “in” in the treatise on place but does not order them; Thomas orders them as Aristotle orders the meanings of “beginning” (and “end” or “limit”) in the fifth book of Wisdom [ed.: Metaphysics V].

• Method: “in” names something sensed and is carried over to less-sensible things by likeness (a kind of ratio); so start from the meaning most obvious to sense and move gradually away, each meaning most like the one before.
• First: in a place — you and I in the room, strictly in a part of the room; water in the glass.
• Second: part in a whole — teeth in the mouth. Boundary case: loosen the teeth so they come in and out, and they are in the mouth as in a place, not as part in whole; a piece sawn out of the table and put back is in it as in a place (like the children’s peg toy); false teeth are in the mouth as in a place; an implant that grows in, and transplants the body tries to reject as alien, get back toward the second sense. Shows how close the second sense is to the first.
• Third: genus in species, generally a part of the definition in the definition — square as equilateral right-angled quadrilateral: a whole composed of three parts; quadrilateral and the differences are in the species square. Striking, since this is in the mind.
• Fourth: species in genus. A student asks why this is not third and the third fourth. His answer: the original meaning of whole is the composed whole, put together from parts; the universal whole is not composed of its parts but said of them. “Particular” comes from the word for part; the Greek for general, katholou, means “according to the whole” (catholic). So dog is a part of animal, but a different kind of whole and part. The definition is a composed whole like the word “cat” composed of c-a-t; but animal is not composed of dog, cat, horse — else “a dog is an animal” would say a dog is composed of dog, cat, horse, elephant. Hence the third sense is more like the original sense. Daily speech: “I’d put quadrilateral in the definition of square” vs. “I’d put dog in the genus animal, tree in plant, courage in virtue” — two senses of “putting in”. Animal is in dog as a defining part; dog is not a defining part of animal. Not two kinds of genus (student’s confusion) but two senses of “in”.
• Is the species actually in the genus? No — only in ability. Recall “our good friend John Locke,” who wanted equilateral, isosceles and scalene actually in triangle in general, which is none of them.
• Fifth: form in matter — the form is at first in the matter only in ability; species (eidos) and form are interchangeable: democracy is one species, one eidos, one form of government. Not like part in whole at all, but like the fourth in being in ability. Fourth is “exactly where it should be, in the middle”: more like part-in-whole than the fifth (third is actually in, fourth and fifth only in ability), and more like the fifth than the third is.
• He finds it strange that senses in the mind precede one in the sensible world, but “you don’t realize how obscure matter really is”; “only Thomas… after Aristotle… could have ordered these meanings.”
• Illustration: clay moulded from sphere to cube — what has changed, the clay or its shape? The average person says the shape. But to say the shape changed is to imagine the genus changing from one species (sphere) to another (cube); really the matter, the clay, has changed, accidentally not substantially. Same with “the weather has changed” (rather than the air), “his mood/attitude has changed” (you changed from sad to joyful), “his habit changed” (I went from virtuous to vicious; the genus habit did not change), “the quality of soul changed from happy to anger” (student), “did the condition of your body change from sick to healthy, or did you?”, blushing: the colour of his face changed vs. his face changed from white to crimson. Two species of colour are different to begin with; it is the face that is now different. We speak as if the genus were a kind of matter — which again shows the likeness of the fourth and fifth senses. “You realize that Thomas has ordered these things perfectly.”
• The class ends at the fifth sense; senses six to eight are not reached in this episode.
• Aside: he first noticed the sphere/cube point when presenting it to his brother Richard.

His words #

• ability; his rendering throughout for the correlate of act [ed.: potency]
• Wisdom, “ninth/eleventh/fifth book of Wisdom” [ed.: Metaphysics]
• Natural Hearing [ed.: Physics]
• kinesis; the Greek behind “motion”, broader than change of place
• the able to be, as such; the second and third parts of the definition; “qua”
• natural mover; a mover subject to motion itself, from the definition of nature
• moved movers vs. unmoved mover
• as such (third part); must include imperfectness and order to a further act
• act of the actual; “form or being, if you wish”, not motion
• De Caelo et Mundo; the books on the universe
• space; the modern substitute for “place”
• locus / location / where; where is the interrogatory, to be where is to be in place
• the empty; what Empedocles denies
• composed whole vs. universal whole; put together from its parts vs. said of its parts
• katholou; “according to the whole”, general/catholic; particular from “part”
• eidos; Greek for species, also form
• in ability vs. actually in; the mark separating the third from the fourth and fifth senses

Texts #

Read in class

• Aristotle, Physics III: “Having divided act and ability according to each genus… the act of the able to be, as such, is motion”; the buildable; things both in ability and in act; the natural mover; bronze and the statue; healthy and sick, colour and visible.
• Aristotle, Physics IV (on place), the eight senses of “in”, as ordered in Thomas Aquinas’s exposition of Book IV (senses one to five).

Mentioned

• Plato, Sophist (being as what can act or be acted upon)
• Aristotle, Metaphysics IX (act and ability); Metaphysics XI (definition of motion repeated); Metaphysics V (meanings of beginning, end/limit)
• Aristotle, Physics VI (infinity in motion), VII–VIII (unmoved mover), the last books of Natural Hearing
• Aristotle, De Caelo et Mundo
• Epistle of James (no shadow of change in God)
• Empedocles (denies the empty); Heraclitus (river); Euclid I.1 (inferred: the two circles)
• Newton; Kant; Einstein; John Locke (triangle in general)

His questions #

• Are the ability to be healthy and the ability to be sick two abilities as walking and talking are? No: I can walk and talk at once but not be healthy and sick at once; in a way one ability, yet not defined the same way.
• Is my fully being in the room my coming into the room? No; motion is the act of my ability to be in the room insofar as I am still able to be in it.
• Is standing in the doorway coming into the room? No; it is accidental to standing there that one comes in more, whereas coming through is on the way to a further act.
• Does the able to be include lack? Lack is involved, but he would not put it in the definition strictly.
• What would lead us to distinguish a body’s place from the body itself? Locomotion: one body leaves, another comes into the same place.
• Why say the body is in the place rather than the place in the body? On the dimension view it is arbitrary (the coinciding circles); on Aristotle’s view the inner surface of the container contains the body.
• Is the species actually in the genus? No, only in ability (against Locke’s triangle in general).
• When clay goes from sphere to cube, what has changed, the clay or its shape? The clay (accidentally); the genus shape does not change from one species to another.
• Could motion be defined through a coming to be that is not necessarily motion? Left open (“let’s wait on that”).