Does physicalism *prove* that the universe is self-subsistent?

Question

I've often heard/read people (Hawking, Dawkins etc) making out that Physics or Physicalism proves that there is no God, or no need for one.

Yet it seems to me that it's an assumption that is smuggled in with the very notion of what Physicalism means. To then go on to say that it proves such a thing is to mistake consequences for assumptions.

Is this correct?

In my understanding, substance is that which is self-subsistent (it requires no cause beyond its own self). Physicalists are starting from the assumption that the universe is a substance when looked at the right way (though they may not use this language). Whereas non-Physicalists do not regard the universe as a substance, and identify it with Brahman, God or Allah (which I note simply means the-One).

One could go on arguing that Physicalism allows one to predict the motion of stars and quantum particles. An Islamic Scholar would say that everything (apart from humans who have free will) follows Allah's will, his law. Physicists only discovered the form of one of his laws.

Answer 1

Physicalism is a hypothesis; it doesn't prove anything. When people say that Physicalism proves that there is no God, they are saying that "If Physicalism holds, there is no God."

So, yes, your analysis is correct.

Answer 2

I believe Dawkins holds that physicalism and the success of modern science proves that the idea of a personal god that intervenes in the world is unnecessary in order to explain the world we observe. In other words, that it's a superfluous concept that has no value in understanding the workings of the world, because physicalism is a sufficient explanation. This then puts the onus on proving the existence or necessity of god, or gods, or spirits, etc on believers in those things.

My understanding is that Dawkins feels no pressure on himself to disprove the existence of god, rather he treats the existence of god, or gods, etc as extraordinary claims that therefore put the onus of proof on the claimants.

Answer 3

It all boils down to definition of proof.

One of features of physicalism is that it strictly defines proof. It gives pretty strict mathematical and logical bonds to what is considered proven, disproven or unknown.

Within this definition, it indeed does disprove God.

Thing is, this definition doesn't overlap with the "common sense impression" of what constitutes a proof. People think they have a pretty good idea what it means "to prove something" and when their pet belief is being challenged, they will keep stretching their personal definitions of "proof" to make the belief survive.

If you can prove probability of an event occurring in given year is 10^-30, physicalism will say it's been proven the event is impossible. A layman may still argue "there is still a small chance".

Especially problematic to accept is that a "proven fact" in physicalism doesn't have any guarantee to be objectively "true". It only needs to fit prerequisites of currently accepted knowledge, experimental data and known facts, and in case any of them is proven wrong by a new, better experiment, it will need to be adjusted. It's a building block in creating the understanding of our universe, "certified approved in further construction".

In effect, the Physicalism definition of "Proven fact" is a specific case of commonly understood "Assumption". From layman's point of view physicists assume nothing can move faster than light, and stick to that belief until proven otherwise.

From religious person's point of view Physicalism assumes there is no God. And conversely, since by definition given holy book is true, if it says there is God, it proves it.