## Ancient vs. CM physics (3)

Classical-modern (CM) physics sees motion as relative to any fixed point, ancient physics sees motion as relative to its own from which and to which. So if I walk to the fridge, on the ancient account I am moving with respect to the couch I left and the fridge I’m going to, whereas in CM physics I am moving with respect to these, your right earlobe, the center of gravity of all the beetles in Peru, or any point that one can specify in on the blackboard-space of the entire universe.

The accounts arise from differences over motion per se. For Aristotle motion as such was a fulfillment of a mobile, and so was relative to its own terms. In CM physics, however, motion is per se relative not to some concrete physical terminus but to the mathematical theater of all motions in space, so one says either that motion is relative either to a subsistent mathematical space or to all the objects in the universe. But it’s probably wrong that there is any subsistent mathematical space, so motions are relative to the universe as a whole.

There is also a way in which ancient physics is relative to the whole universe: all physical motion reduces to change of place, and all places reduce to the whole of the universe. So all accounts of physics agree that qua physical, the ultimate description of anything is that the universe is universing.

The division between ancient and modern physics is not over any action qua physical, but over the way in which we are explaining things when we explain them as physical. One can explain shapes and squares as figures, but there is nothing more to being a shape than being a figure while there is more to a square than being one. The question is thus whether there is a formal difference that one adds to the motion that goes beyond place-shifting. For Aristotle there was, since, as mentioned above, beyond place-shifting there was fulfillment or the good, and since this belonged to all physical things as physical there was another axis of description than just that the universe was universing. It was because motion reduced to goodness or perfection that it was defined not just relative to the universe but relative to its terms.

Here again, however, we might not have a real difference between Ancient and CM physics but only the difference between an Ancient summary sketch of the whole and a CM attempt to fill out all details. If the universe is universing, universing is its fulfillment. Acting universe-ly can’t be the whatever-happens in the universe any more than acting squirrel-ly could be whatever happens to a squirrel, since the latter occasionally includes being hit by a truck or being ten feet from a cow, neither of which describe what squirrels are. A complete physics – any physics – requires an account of what is fulfilling or good for a universe. CM physics seems to want to work toward this sort of explanation from the bottom up, filling out all the details until one gets a view of the whole; Ancient physics gives a summary sketch of the whole trajectory of the discourse and tries to fill out the details with subsequent sciences. Either approach runs the risk of losing sight of the ultimate goal: one complaint against Ancient physics is that it was too quick to think it had figured out the various goods of the things it studied (mountains are there to make men remember the loftiness of creation or whatever) but it’s just as incisive a critique to point out that CM physics loses sight of the good of the universe that is required in order for it to be universing at all.

Plato is still right about the causality of the good, even if science is ten thousand years from being in a position to get the first glimpse of what the good is.