The world of physics is an abstract world and not the whole of reality

As Ed Feser notes:

"As I have emphasized many times, what physics gives us is a description of the mathematical structure of physical reality. It abstracts from any aspect of reality which cannot be captured via its exclusively quantitative methods. One reason that this is crucial to keep in mind is that from the fact that something doesn’t show up in the description physics gives us, it doesn’t follow that it isn’t there in the physical world. This is like concluding from the fact that color doesn’t show up in a black and white pen and ink drawing of a banana that bananas must not really be yellow. It both cases the absence is an artifact of the method employed, and has nothing whatsoever to do with the reality the method is being used to represent. The method of representing an object using black ink on white paper will necessarily leave out color even if it is there, and the method of representing physical reality using exclusively mathematical language will necessarily leave out any aspect of physical reality which is not reducible to the quantitative, even if such aspects are there.

"But it’s not just that such aspects might be there. They must be there. The quantitative description physics gives us is essentially a description of mathematical structure. But mathematical structure by itself is a mere abstraction. It cannot be all there is, because structure presupposes something concrete which has the structure. Indeed, physics itself tells us that the abstraction cannot be all there is, since it tells us that some abstract mathematical structures do not fit the actual, concrete material world. For example, Einstein is commonly taken to have shown that our world is not really Euclidean. This could only be true if there is some concrete reality that instantiates a non-Euclidean abstract structure rather than a Euclidean abstract structure. So, physics itself implies that there must be more to the world than the abstract structure it captures in its purely mathematical description, but it does not and cannot tell us exactly what this concrete reality is like."

1 comment:

  1. This is one of my ongoing battles with Steve Landsburg. He denies the contention you need the structured thing to have the structure.

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