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Do Physicalists Believe in Black Holes?

Michael Egnor

black holes

Many Darwinists object to the sobriquet “materialist” — they consider themselves physicalists. Responding to an article by Bernardo Kastrup, “Consciousness Cannot Have Evolved,” Darwinist Jerry Coyne explains:

Kastrup is dead wrong that materialism requires all entities to be measurable. [It is] is dead wrong that materialism requires all entities to be measurable. Here’s a question: do you have a liver? The answer is based not on measurement, but on observation. I have never heard a definition of “materialism” that requires quantitative measurement, but … it seems to be one [that is] confected to rule out consciousness as a material phenomenon, or the result of a material phenomenon. Unfortunately, [that] rules out a lot of material phenomena that can’t be quantified as well, like “love”. (I’ll let readers quibble about that one.)

Here, for instance, is the definition of “physicalism” (which is said to be the same as “materialism”) from [the] authoritative Stanford Encyclopedia of Philosophy (my emphasis):

“Physicalism is the thesis that everything is physical, or as contemporary philosophers sometimes put it, that everything supervenes on the physical. The thesis is usually intended as a metaphysical thesis, parallel to the thesis attributed to the ancient Greek philosopher Thales, that everything is water, or the idealism of the 18th Century philosopher Berkeley, that everything is mental. The general idea is that the nature of the actual world (i.e. the universe and everything in it) conforms to a certain condition, the condition of being physical. Of course, physicalists don’t deny that the world might contain many items that at first glance don’t seem physical — items of a biological, or psychological, or moral, or social nature. But they insist nevertheless that at the end of the day such items are either physical or supervene on the physical.

That seems pretty accurate, especially with “supervene on the physical” at the end (for that is what consciousness is), and it says nothing about quantitative characterization.

Extended Stuff, Thinking Stuff

The observation that materialism implies measurability derives from the Cartesian splitting of the world into res extense (extended stuff) and res cogitans (thinking stuff). Modern materialists are basically Cartesians who have jettisoned res cogitans. Everything, to materialists like Coyne, is extended stuff and the relationships between extended stuff. Everything is in some real sense measurable. 

Obviously, this materialist view of reality leaves out much of reality (love, reason, mercy, truth, etc.) so skittish materialists like Coyne often call themselves “physicalists,” which means that they only accept as real things that can be observed and tested by physical science. 

Physicalism Versus Modern Science

But with 20th-century science, even physicalism is untenable. For example, physics demonstrates the reality of singularities — black holes and the Big Bang itself — that are by definition not observable or testable by physical science. Singularities are undefined terms in Einstein’s equations of general relativity — terms in which the denominator goes to zero. They are quite real, but they are not physical in any sense — they are undefined by the methods of mathematics and physical science. Now of course the consequences of singularities can be observed and defined — the residual background radiation of the Big Bang, or the behavior of matter in the vicinity of a black hole are certainly observable. But the Big Bang singularity itself and the singularity at the core of each black hole are not natural — they are not a part of the natural world, and they are not things that we can know by the methods of physical science. If we could know them, they wouldn’t singularities — they wouldn’t be black holes or the Big Bang. 

Some of the most important advances in modern science entail the recognition of the existence of very real things that are unknowable by natural science. The supernatural is very real, and the materialist/physicalist denial of this reality is a rejection of modern science.

Editor’s note: See also:

How Black Holes Figure in the Argument for Cosmic Intelligent Design

First Ever Black Hole Image Points to Cosmology’s Big Message

Photo credit: Event Horizon Telescope [CC BY 4.0], via Wikimedia Commons.