St. John's

Motion and Being in Aristotle

03 March 2024

Class: Philosophy Tutorial — Spring 2024

The role that motion and nature play in the arguments Aristotle makes in the physics and metaphysics is unclear to me. Book 12, Chapter 8 examines the motion of the planets, and as I revisit the chapter, it continues to stick out as tangibly different from the rest of the readings in Book 12 and the rest of the metaphysics which seem to have more to do with intangible aspects of existence.

Why a cosmological model might influence an understanding of thinghood is not apparent, but I would like to make an attempt to discover the purpose of book 12 chapter 8, and how it fits with the rest of the book.

Book 12, chapter 8 is chiefly concerned with the motion of the heavens and the planets. The motion of the planets seems to be the most important thing about them. I will begin then by examining motion more closely.

Physics book 1 chapter 1 states that to learn about what we do not understand, we must proceed from what we do understand. The world around us is in motion. The plants and animals grow and decay. The weather changes from hot to cold and from rainy to dry. The fires burn hot, and the ashes grow cold. The observable motion of nature is clear to us. The motion observable in nature is a starting place for other investigations.

"it is necessary to lead ourselves forward [...] from what is less clear by nature but clearer to us to what is clearer and better known by nature [...] Thus it is necessary to proceed from what is general to what is particular for it is the whole that is better known by perceiving and what is general is a kind of whole" [1][184a20]

However, just because something is observable does not mean that it is well-understood. Book 1, chapter 1 of the physics asserts that when something is known, its causes or sources are well understood.

"For we regard ourselves as knowing each thing whenever we are acquainted with its first causes and first beginnings, even down to its elements"

The goal, then, is to understand the causes of motion.

Aristotle in physics describes nature as a cause of motion in those beings which are the source of their own being moved and coming to rest.

"Nature is a certain source and cause of being moved and of coming to rest in that to which it belongs primarily in virtue of itself" [1][192b22]

That there is a class of things that have in them their own source is knowable by observation. One has only to observe to learn that squirrels come into being from squirrels and houses come into being by the activity of craftsmen not from other houses. This observation allows Aristotle to separate a specific type of motion for examination, but more interestingly, since natural beings contain the cause of their motion, they provide an observable link between motion and being. It may be, then, that the examination of the motion of the planets in Chapter 8 merely provides an observable starting point from motion into being. Lending some evidence to this hypothesis, Aristotle does not dwell on the motion of the natural beings but quickly begins to examine their being.

"And everything that has a nature is an independent thing since it is something that underlies [and persists through change]" [1][192b35]

Natural beings are described as independent things because something about them persists in the change. A human gives birth to humans; a tree produces trees, and the squirrels produce squirrels. Natural things are also growing things. If the natural things are the source of their own being, are they also the source of their growth? Does the boy contain the man? Does the acorn contain the tree? Aristotle seems to say both yes and no. Nature, the source of the growth, is both form and material.

"In one way then, nature is spoken of thus, as the first material underlying each of the things that have in themselves a source of motion and change, but in another way as the form" [1][193a29]

"But the growing thing, insofar as it grows, does proceed from something into something. What then is it that grows? Not the from-which but the to-which. Therefore nature is the form." [1][193b20]

Aristotle seems to claim that there is some manhood or treehood to-which the growth of natural bodies comes. The growth proceeds not from the beginning but from the end. This assertion boggles my modern Newtonian understanding of cause and effect. Luckily, Aristotle in chapter 3 of book 2 of the physics lays out what he means by cause.

"but all the causes now being spoken of fall into 4 most evident ways [...] that out of which [..] what-it-is-for-it-to-be, a whole or composite or form [...] and generally the maker, are all causes as that from-which-the source of change or rest is, but the other things are causes as the end of the good of the remaining ones. For that-for-the-sake-of-which means to be the best things and the end of the other things." [1][195a10]

Cause to Aristotle means not just an action that results in motion (from-which-the-source-of-change) but also the material from which something is made (that out of which), the form into which that material is arranged (what it is for it to be) and a purpose for which the motion is (that for the sake of which). Aristotle also seems to privilege the that-for-the-sake-of-which above other causes.

"And the most ruling of the kinds of knowledge, or the one more ruling than what is subordinate to it, is the one that knows for what purpose each thing must be done; and this is the good of each thing, and in general the best thing in the whole of nature" [2][982b]

The final cause of the motion of natural beings then might also provide insight into being just as observations of motion allowed a classification of beings as natural or not.

In the physics, nature is said to be an end itself. "But nature is an end and a that-for-the-sake-of-which." [1][194a28]. I think this means that the cause of the men begetting men and boys growing into men is an end to itself, not that the actual motions of begetting and growing are ends to themselves. While nature serves as a bridge between motion and being, nature, being a sort of activity itself, can not be that for the sake of which of motion in general, or else, as Aristotle argues (book 12, chapter 8, around 1074a20), there would be an infinite chain of motions for the sake of which, which is absurd. Aristotle continues the argument to conclude that motion must be for the sake of something motionless. Here, it is a being that causes motion.

"Therefore the first motionless being that causes motion is one both in articulation and in number" [2][1074a35]

Being may not indicate a self-aware intelligence but merely something that exists as an independent thing. We can recall Things that persist in change are independent things. The claim at 1074a35 might be parsed as: Therefore the first motionless thing that persists through change that causes motion is one both in articulation and in number. This smaller claim needs no further investigation at this time.

Aristotle seems to include astronomy in the study of nature because the planets move. Book 2, chapter 2 describes the mathematician as separating the natural bodies from their properties.

"The more natural of the mathematical studies, such as optics, harmonics, and astronomy also show this for in a certain way they stand contrariwise to geometry" [1][194a5]

I believe this is the core link that brings the purpose of book 12 chapter 8 into focus. The motion of the planets, being perpetual and perfect, is less knowable than natural motion. But natural motion shows us something about the motion of the planets and the motion of the planets provides an anchoring into the investigation of that which is eternal and perfect. The argument might be in the following form.

1. Motion can not be for the sake of itself
2. Motions are directed into the heavens (because this motion is eternal and perfect?). The final cause of motion is itself motionless
3. Motion is a mirror into being
4. Being can not be for the sake of itself
5. Being is directed to some eternal and perfect being
6. The final cause of being is itself beingless (without substance?)

Chapter 10 seems to put the crown on this argument with its final line "Let there be one lord" implying a unification of the motionless mover and the beingless being. This final statement would be unnecessary if the investigations of motion were simply illustrative of being and not an investigation into an important quality of a perfect thing. Causing motion can not be accidental to the prime mover for a perfect being could hardly do anything by accident. Motion then must be not merely a starting point for understanding being but an aspect of the divine equal to being.

Bibliography

[1] J. Sachs and Aristoteles, Aristotle's physics: a guided study. New Brunswick, N.J: Rutgers University Press, 2008.

[2] Aristotle, Aristotle's Metaphysics. Santa Fe, N.M.: Green Lion Press, 1999.