Apparently, Michael Egnor just can't get enough of making himself look like an idiot. His latest screed is an attack on me, for criticizing his dismissal of evolution as a tautology.
My observation that "Natural Selection" is a tautology, and therefore useless to modern medicine, seems to have set off quite a few Darwinists. Prominent Darwinist blogger Mark Chu-Carroll took me to task here, and comes up with an approach that he believes gets "Natural Selection" off the tautological hook: he asserts that all scientific theories are reducible to tautologies! Mark writes:
And this brings us to Egnor's idiocy. It's a common tactic among idiots to criticize various scientific theories as tautological... [but] you can derive a tautological statement from any scientific theory. The theory of gravity? If you let go of something, it will fall - therefore, if you let go of something, it will fall. Relativity? Light bends when it passed through a gravitational field - therefore, if I shine a light through a gravitational field, it will bend. Evolution? The things that survive to reproduce are the things that survive to reproduce.
Mark errs. A tautology is a statement that is true by its logical structure. 'A is A' is a tautology, and 'survivors survive' is a tautology. It's logically true, and it cannot be false. Scientific theories generally cannot be reduced to tautologies. Newton's law cannot be reduced to 'If you let go of something, it will fall-- therefore, if you let go of something, it will fall'. Newton's law of gravitation, in its most 'reduced' form, states that the gravitational force acting between two masses is proportional to the product of the masses and inversely proportional to the square of the distance between the centers of the masses, and that the constant of proportionality is the gravitational constant. Newton's law is not a tautology, and it can't be reduced to a tautology. It is not logically true. It's empirically true, but it could have been false. The force of gravity could have been proportional to the inverse cube, not the inverse square. Neither is Einstein's theory of relativity a tautology. The curvature of space-time is given by Einstein's tensor equations. They've been confirmed experimentally, and they're not the least bit tautological.
As usual, Egnor is being a typical IDist idiot - playing games with selective quoting, definition shifting, and general bullshitting.
Let's start with the game he's playing with the definition of tautology, and what I actually said. Here's the relevant quote from my original post:
3. "(A⇒B)∧A⇒B" - A implies B and A implies B. This is just a basic statement of one of the fundamental inference rules of logic. Once again, it doesn't matter what A means, or what B means; and it doesn't matter whether A or B are true or false. No matter what, by virtue of the structure of the statement, it must be true.
That third tautology is particularly important - because it's an example of a fundamental principle of logic. If you take any proof - any sequence of statements and valid inferences from those statements - and you combine all of the statements of the proof together, the resulting statement is, by definition, a tautology. The obvious implication of this is that you can take any statement which is provably true, and present it as a tautology.
Notice the important thing that Egnor chose to omit?
He quotes me as saying that any scientific theory can be reformulated into a tautology - in fact, any statement provable by inference can be reformulated into a tautology by simply folding the inferences into the statement. Any theory can
be stated as a tautology by folding the observations and inferences into the statement of the theory.
A tautology is a statement which is true by its logical structure. What's a proof of a statement in logic? It's a set of basic statements (axioms) which can, by using the inference rules of the logic derive the proven statement. Translate that down a bit and - what's a proof? It's a series of statements that demonstrates that a final statement is inevitably true by the logical structure of the proof. So form the proof up into a single statement (by joining steps with appropriate "and" and "or"s), and the proof is a tautology.
The same holds for scientific theories - except that in general, scientific theories add observations to the set of basic statements.
Egnor tries to use Newton's law of gravitation as a constrast against evolution: an example of a theory that cannot be reduced to a tautology. He does that by trying to throw a lot of terminology in to make the law of gravity look as impressive and complicated as possible, while simultaneously presenting the most silly reductionist statement of evolution that he can. But even so - let's try playing his game. What does Newton's law of gravitation say?
- When we observe the behavior of physical bodies, we observe that
all physical bodies appear to be attracted to one another.
- If we carefully measure the masses of bodies, we observe that the force of attraction
between two bodies separated by a specific distance appears to be proportional
to the product of their masses.
- If we carefully measure the distance between two bodies of known mass, we observe
that the force of attraction between them appears to diminish as the inverse square
of the distance between them.
- Therefore, we conclude that two bodies of known mass m1 and m2, separated by a distance r will attracted towards each other with
a force proportional to (m1×m2/r2).
Strip away the excess verbiage, and that reduces to: we observe that two bodies are attracted by a force proportional to (m1×m2/r2), therefore, we we assume that for all pairs of bodies, the bodies will be attracted by a force proportional to (m1×m2/r2). Quite tautological when you structure the statement as a tautology, right?
Or to reduce it to the silly level of statement that Egnor insists on using for
evolution: if we let go of something, it will fall towards the ground; therefore, if
we let go of something, it will fall towards the ground.
That reduction that I just made - that silly, ridiculous reduction of gravity to "things fall, therefore things fall" - is almost exactly on the level of Egnor's reduction of evolution. It strips away nearly all of the relevant parts of the theory in order to reduce it to a true, accurate, by trite statement that's easily dismissed as a silly tautology.
Egnor's full-fledged argument is that the theory of evolution is irrelevant to the development of antibiotic resistance, because it reduces to "bacteria that don't die when exposed to antibiotics don't die when exposed to antibiotics." But that statement leaves
out a crucially important part of the phenomenon. Just like my reductionist statement
of gravity doesn't say anything about how fast things will fall or how
things are attracted to bodies other than the earth, or anything else that the
theory of gravity could tell us, Egnor's reductionist statement leaves out the crucial
explanation of why there are bacteria that don't die in the first place.
As I keep saying: we can, experimentally, take a single bacteria, and produce a clone-line culture from it. If we then expose it to antibiotics, some of the bacteria won't die. Dr. Egnor's tautology applies: the bacteria that don't die, don't die. But the original cell was not antibiotic resistant! So why are there any bacteria in the culture that don't die?
Egnor can't answer that. So he plays games to avoid the central issue - to avoid the question that he can't answer.
One more quick example of Egnor's idiocy, and I'll stop. Later in his post, he says:
A salient characteristic of a strong scientific theory is the combination of its logical improbability and its empirical verification.
"Logical improbability" is a meaningless term. Egnor is playing the "Mr. Spock" game of logic - trying to use the credibility of formal mathematical logic to give weight to something that has nothing to do with logic.
I've also never heard of a scientist who says that to be a good theory,
a theory must be improbable. In fact, I'm not even sure of what it means for a theory to be improbable in a formal sense, and I'm pretty sure that no real scientist discards theories because they don't seem improbable enough.