Recently I had a long phone conversation with a friend who is working on a doctorate in philosophy. I expected a few questions about book recommendations and how to worship with the present pandemic, but the conversation was mostly spent on the object of his study, namely, the actions of the simple substances (angels) upon man. Without going into the points around which our conversation turned, the chief effect was that I wanted to fill in those gaps in my reading concerning the angels, what they are and what we can know about them, both from reasoning and from faith.
The first book I picked up to this end contained the Enneads of Plotinus, a philosopher who certainly speculated on the multitude of incorporeal beings. But realizing how “out of shape” I was philosophically, I retreated to more familiar ground. I found my copy of Aristotle’s Metaphysics, and started reviewing sections I did not remember well, namely, Book IX on actuality and potency and Book X on unity. Unlike a novel, where one can read continuously and reasonably hope that what is obscure will become clear later on, when something is obscure in Aristotle, I have to slow down. The questions I ask myself the most often when reading Aristotle are “Is this true?” and “How do I know that?” This is especially true when he talks about motion, about which he makes many universal statements. Aristotle did not grow up hearing about the big bang, the expanding universe, inertia and universal gravitation, atomic models, waves and particles, the death of stars, and so on; therefore, a contemporary person is reasonably skeptical when such a person makes a universal statement about motion itself. And yet, I have the same “macro” experience that Aristotle did. I should at least be able to understand why he thinks certain truths are self-evident or demonstrable.
After Books IX and X, I skipped Book XI (which is a rehash of the Physics and earlier sections of the Metaphysics), and moved on to Book XII, where Aristotle eventually begins his consideration of substances that are immobile. And though I’m eager to understand the immobile sort of being, I still have to work through his more general consideration of substances. The first few chapters are basically a recounting of the principles of change as presented in the Physics (the matter, the contrary to which, the contrary from which). He goes to talk about how substance is also spoken of in three ways: in reference to the matter of something, in reference to the nature or form, or in reference to the composite substance (matter and form together). It is here that the question arises, Is it possible for substance to exist apart from composite substance? He gives an example to illustrate: the form of the house does not exist apart from the house. But this example at the same time allows his to say, unless the art of building exists apart. So there is some sense in which the form of the house exists in the mind of the builder, but in a different way than it exists in the actual house. He extends this consideration to all of the arts, in which the artisan has the form in his mind. He then states If the ‘this’ [substance] exists apart from the concrete thing, it is only in the case of natural objects. He credits Plato with understanding this, to the extent that he posits as many Forms as there are kinds of natural object. And yet Aristotle (while explicitly reserving the possibility that the rational soul survives the body) says there is no necessity for the existence of Ideas, for concrete man is begotten of concrete man, and the medical art (which is the form of some mind) is the formal cause of health.
At this point, I reflected for a bit on the fact that Aristotle did not limit himself to the abstract considerations of being and motion, but extended lengthy and perhaps more difficult efforts on his extensive research into animals, their parts and their kinds. If the Forms were really as many as the kinds of natural things, then it is reasonable to seek knowledge of the Forms (which are presumably finite though great in number), by seeking to know every sort of natural thing. Plato (as far as I know) made no such effort, perhaps convinced by Socrates that recollection by dialectic was the chief means of arriving at truth. But for Aristotle, who firmly places the beginnings of human knowing in the senses and finds most objects of knowledge in the sensible world, it makes sense to direct his energy toward that same natural world. Certainly it is an exaggeration to say, The primary difference between Aristotle and Kant, is that Aristotle wrote lengthy treatises about animals. And yet, there’s something to it. (Doing a quick bit of research just now, it appears that Kant was actually quite involved in natural science early in life, especially making theories about the formation of the Solar System; nevertheless, the categories of the transcendental aesthetic do not seem like they would lead to any knowledge of living things. I guess I need to review Kant…)
I also spent time reading about the formation of the heart (the first organ to develop in vertebrate embryos, including humans) and about jellyfish, some of which have neither brains nor hearts. Why? To understand Aristotle’s statements about motion. He says, “There is no continuous movement except movement in place, and of this only that which is circular is continuous.” I’m virtually certain he has the (physical) Heavens in mind here, but I always find this difficult to think about from his perspective. With Newton, I’m inclined to think that celestial objects above do not naturally move in circles but have an inertial motion which is impeded by a heaviness toward a larger body, resulting in a circular movement. (I must confess that it is remarkable that the objects in question are so arranged that their inertia and gravitational pull are balanced so perfectly that they end up going in circles for as long as they do, yet I cannot think it is due to a natural circular motion). How the heavenly bodies, with their circular motions above would even cause motions here below (from Aristotle’s perspective) is not even obvious to me, apart from being seen, so I started to look more locally.
I picked up my coffee cup. Though the cup is moved by me, and even the parts within me are moved one by another, I cannot discern that I am physically moved by anything outside me. (Yes, the coffee moves me as an object perceived, but not as an efficient cause, for indeed, I am moving the coffee.) So I am able to move myself. But it is not possible for something to come from nothing. So there was already a motion going on inside me. Indeed, there are lots of motions going on inside me, but the one that stood out was the motion of the heart which stands at the center of the circulatory system. I, not moved by any mover, could not initiate movements of my own, unless I possessed a movement that does not cease, but the only sort of motion that does not cease is a circular motion.
I thought about other self-moving things then. I thought briefly about jellyfish without hearts, but did not arrive at a conclusion there… Then I thought about battery operated objects. Again, these move without anyone pushing or prodding them to move, and this depends on a motion existing already inside of them. This is the chemical reaction occurring within the battery, which is not eternal, but which will continue as long as there are substances in it which can interact. This battery is the center of a circuit, and so again we have a circular motion which is necessary to account for an object which moves itself.
…And now I have to prepare for a conference call. Though chapter 6 of Book XII is where the consideration turns more directly to immobile substance, I feel like I still have very much to consider about motion. Given that St. Thomas’ first way of proving God’s existence depends ultimately on the fact that something moves, I think there is a lot we can learn from analyzing motion.