School is in a bit of a rough patch just now. for a variety of reasons. Both the classes I’m in are a little out at sea in respect both to understanding the material and in matters of social etiquette/group dynamics. We’re still working on Euclid in tutorial, and just finished three or so reductio ad absurdum proofs, which seek to prove something by showing that the alternative is inconceivable. They’re kind of irritating; I like the next set much better, which are about how to construct right angles by bisecting triangles, given different situations (a given angle, a given finite line, a given point on an infinite line, and a given point off of a given infinite line). In seminar we’ve been doing Aristotle’s Physics, and will continue therewith for the next week. Last night’s question was about why A claims it to be impossible that there be both infinite body and place. I was in no way helpful in the ensuing discussion, and ought to try harder to understand A. before coming into class next time, because it’s not like most works where I can just read it and automatically discuss it comfortably. That’s what I said Monday: my resolution is still awaiting implementation.
If I had to account for what I got out of our last reading it would probably be A’s claims that just because something is more or less difficult to imagine, especially about the edge of the universe, doesn’t make it more or less the case in actuality; and that the universe is a contained place outside of which there is no place and no movement. In the first case, just because, should we imagine standing on the edge of the universe and throwing a spear and having it continue somewhere past that edge (the reason Lucretius supposes the universe to be infinite), it doesn’t mean that is the case in actuality, any more than positing an infinity of possible numbers means that there is an infinity of the actual objects we use those numbers to count. There is such a thing as infinite divisibility and infinite time, as well as infinity of potentiality, but not infinite body, because infinity is a property of the continuous rather than of bodies.
Also, A’s sense of place is not the same thing of what we mean by space in a way that is difficult to imagine much less articulate. In a way he’s trying to compensate for lacking a concept of gravity. Thus, the universe has a center which resides where we would imagine the earth’s core to be. The principle of a thing’s motion resides in that thing, and each element has a natural motion to go in a particular direction in relation to the center. Thus earth and water find their natural place as near the center as possible, and are constantly trying to go there, while air and fire are lighter and naturally want to go up to a place at some remove from the center, and the celestial bodies have a natural place near the limit of the universe (this limit being likened to a jar which shares the same shape with what is contained, providing it with a place in which to be — I see it as a kind of force field around with there is nothing, including place or movement… non-dimensional nothing).
Why should you or I or anyone care? I’m not sure. It’s kind of poetic; if I were writing sci-fi stories it would no doubt be handy to have these things stored in my imagination. But otherwise… I’m just not sure.