Thursday, September 27, 2012

Physics & Metascience (Metaphysics)

George Mason University physicist (and author of TheTheory of Almost Everything) Robert Oerter, discussing act in potency in in physics, writes "it seems to me that the concepts of time and change are metaphysically prior to those of potentiality."

My response:
The French physicist, philosopher and historian of physics Pierre Duhem would agree with you, Dr. Oerter, that physical theories do not depend upon a choice of metaphysics. Duhem masterfully shows this, with many historical examples, in his classic philosophy of science work The Aim and Structure of Physical Theory (excerpt). He also treats this in "Physics & Metaphysics," "Physics of a Believer," and this excerpt from To Save the Phenomena.
His reply:
Thanks, that's very helpful. From the second link:

"That Physics Logically Precedes Metaphysics

...We cannot come to know the essence of things except insofar as that essence is the cause and foundation for phenomena and the laws that govern them. The study of phenomena and laws must therefore precede the investigation of causes."

That's what I was groping for in my attempts to answer Feser.

However, I think there's a distinction that must be made between the metaphysical essences that Duhem is talking about and the metaphysical principles that Feser is talking about. Don't we need concepts of cause and change before we can even begin a physical investigation?
My response:
Your question appears to be a question on the method and division of the sciences. Boethius, following Aristotle, proposed that the "Speculative sciences may be divided into three kinds: physics, mathematics, and metaphysics.":
  1. Physics [(the natural sciences)] deals with that which is in motion and material [(ens mobile or "mobile being")].
  2. Mathematics deals with that which is material and not in motion [(∵ mathematical objects, or "mathematicals," do not move or change)].
  3. Metascience deals with that which is not in motion nor material.
(cf. §II of his De Trinitate)

In this context, Thomas Aquinas writes in his Division and methods of the sciences, a commentary on Boethius's De Trinitate questions V and VI (my adapted translation follows):
q. 5 a. 1 objection 9: That science on which others depend must be prior to them. Now all the other sciences depend on metascience because it is its business to prove their principles. Therefore Boethius should have placed metascience before the others.

reply to objection 9: Although metascience is by nature the first of all the sciences, with respect to us the other sciences come before it. For as Avicenna says, the position of metascience is that it be learned after the natural sciences, which explain many things used by metascience, such as generation, corruption, motion, and the like [(e.g., actuality, potentiality, matter, form, etc.)]. It should also be learned after mathematics […]. […] Nor is there necessarily a vicious circle because metascience presupposes conclusions proved in the other sciences while it itself proves their principles. For the principles that another science (such as natural philosophy) takes from first philosophy [(i.e., from metascience)] do not prove the points which the first philosopher [(metascientist)] takes from the natural philosopher, but they are proved through other self-evident principles. Similarly, the first philosopher does not prove the principles he gives the natural philosopher by principles he receives from him, but by other self-evident principles. So there is no vicious circle in their definitions. Moreover, the sensible effects on which the demonstrations of natural science are based are more evident to us in the beginning. But when we come to know the first causes through them, these causes will reveal to us the reason for the effects, from which they were proved by a demonstration quia [(i.e., a demonstration a posteriori, a demonstration from effects to causes)]. In this way natural science also contributes something to metascience, and nevertheless it is metascience that explains its principles. That is why Boethius places metascience last, because it is the last relative to us (quoad nos).
  1. the natural sciences are epistemologically prior to metaphysics  
  2. metaphysics, which he proposes we term "metascience," is the true philosophy of science.