Can you please point me to an argument by a notable contemporary philosopher arguing why we may know the fundamental (metaphysical) nature of space and time?
In a recent answer to a question I wrote that we cannot, to which @modalmilk commented "there are plenty of professional philosophers who ... think we can know the nature of space and time".
There seems to be plenty of discussion about the metaphysics of space and time, but I was surprised that I did not find anything corresponding to why in principle we may or may not someday know the fundamental nature of space and time.
Here is my take on this:
One might suppose that we may someday come to know the fundamental nature of space and time through physics, but I have a problem with that.
In chapter 12 of The Feynman Lectures on Physics Richard Feynman says:
in order to understand physical laws you must understand that they are all some kind of approximation.
And earlier in the very first chapter he says:
most interesting, philosophically we are completely wrong with the approximate law. Our entire picture of the world has to be altered even though the mass changes only by a little bit. This is a very peculiar thing about the philosophy, or the ideas, behind the laws. Even a very small effect sometimes requires profound changes in our ideas.
for example, in Newtonian physics one could imagine a snapshot of the state of the entire universe in a single moment in time (a plane of simultaneity) but the small changes of special relativity to the approximate laws of Newton, made that impossible - today we believe it is meaningless to ask what is happening now somewhere else:
Alpha Centauri “now” is an idea or concept of our mind; it is not something that is really definable physically at the moment.
So if Feynman is correct, physics is out of the window; what next? maybe direct experience? after all we seem to have an experience and an intuition of space and time.
here the problem seems to double; now we need to answer both what is the fundamental nature of our experience of space and time, and what is the fundamental nature of the elements of reality these experiences correspond to.
Take for example the color blue; we can ask what is the fundamental nature of the experience of blue - and since we know that blue corresponds to a particular frequency of light, we need to also ask what is the fundamental nature of light; but what can we say about the fundamental nature of blue color, except maybe in the spirit of Zaphod Beeblebrox, blue's just this color, you know?
then, we can also ask what we can expect to learn from our experience of space and time about the elements of reality they correspond to; why should our experience of space correspond to real space any more than blue corresponds to a bombardment of photons?
on the other hand, there seems to be something in the nature of our experience of time that makes physicists and philosophers try to dispose of it as an illusion; one example is eternalism and another is that of Julian Barbour who advocates the view that "time, as we perceive it, does not exist as anything other than an illusion".
However, when it comes to our experience, time actually seems to be more persistent than space; all we need to do to make the experience of space disappear is close our eyes; and we have several kinds of experiences which do not seem to involve location, such as anger or smell, and just as we can experience blue without light, in a dream, we can experience space without real space, as an illusion; but can we similarly have an illusion of time? wouldn't the dreamworld illusion of the flow of time require real time to flow? this reminds me of the omnipotent being failing to deceive Descartes into believing he does not exist.
In fact, Stephen LaBerge showed dream time flows at the usual rate: "time perception while counting during a lucid dream is about the same as during waking life".
so, in general, it seems that our experience of space and time is not a promising avenue to knowing the true fundamental nature of the corresponding elements of reality.
but what does it even mean to know the fundamental nature of space and time? the experience of colors is literally in our face, and yet philosophers cannot say much about their mysterious phenomenal existence; is this because of a limitation of language? or of our ability to comprehend? is this possibly what Wittgenstein meant by:
Whereof one cannot speak, thereof one must be silent.
If this is so for direct phenomenal experience, why should we expect the fundamental nature of space and time, or matter, or existence itself, to be any more comprehendible to human intellect? isn't that pure vanity?
we can hardly even fathom the physical facts we discovered, such as the incredible size of the universe, or quantum mechanics; as Richard Feynman put it:
If you think you understand quantum mechanics, you don't understand quantum mechanics.