In a sense, we could call Natural Selection "therapy for mutated genes". Maybe Wittgenstein was thinking about his type of "therapeutic philosophy" in a similar way. He tells us to view language as an enduring, inevitable source of error. "Our language continually ties new knots in our thinking. And philosophy is never done with disentangling them." In biology, we could say that mutations of genes are a continual source of error, and natural selection is never done eliminating them from the gene pool. Of course, Wittgenstein is concerned with the evolution of human ideas, not the evolution of organisms.
"Philosophy simply puts everything before us, and neither explains nor deduces anything." Compare that to:
"Evolution simply puts the various types of living organisms before us, and neither explains nor deduces anything."
"what is hidden is of no interest to us" Compare that to:
"phenotypes that cannot be generated (by mutation) or that cannot survive are of no interest to the biologist"
It would be easy to assume that philosophy should assume the role of a "Mutation Mechanism", throwing up new ideas and new possibilities while science would be the "Selection Mechanism", eliminating bogus hypotheses. However, in the domain that was of most interest to him, maybe Wittgenstein saw past this easy dichotomy. Within the domain of language, philosophy need do little work in birthing new ideas. The human mind, without the need for any self-conscious philosophers, is able to produce plenty of new ideas. "Folk Psychology" automatically provides us with a feeling that, "everything about mind and language is already before us".
The later Wittgenstein suggested that philosophy is fundamental to science, that philosophy can serve a purpose before the klank and whir of empirical science has a chance to engage. Does philosophy begin the process of natural selection while science completes it?
In biological evolution there are two stages of natural selection:
1) Some mutations kill embryos. We could call these "errors in biological logic", changes in a phenotype that make it impossible for the new individual to even mature correctly.
2) Other mutations conform to the internal logic of the organism, but can be seen as "error" only when the organism confronts the hard external challenges of the environment.
Maybe it is these two phases of selection that Wittgenstein mapped onto philosophy and science, respectively? Philosophy can eliminate some bogus ideas simply by the application of logic. In this task, philosophy has no need for the special methods of science. Once philosophy has cleared away all the illogical ideas that die in utero, then an idea can be born into the outer world of science to face the selective pressures for survival that empirical methods can exert.
I initially looked for evidence that Wittgenstein may have read Darwin. However, before the discovery of the Double Helix and the Genetic Code, many scientists still tried to ignore Darwin because the mechanism of mutation had not yet been understood in molecular detail. Wittgenstein died just as science was completing the final vindication of Darwinism. Evolutionary thought was dominated by non-Darwinian ideas in Wittgenstein's time, so I am shifting my search in an attempt to find evidence that Wittgenstein was interested in non-Darwinian evolutionary ideas. For example, Wittgenstein was interested in Stalin's Soviet Union where Lysenco was elevating non-Darwinian evolution to the status of the officially state approved, "politically correct" biological theory of evolution.
Garth Hallett provides a long list of authors cited in various Wittgenstein writings. In searching for evidence that Wittgenstein knew about evolution, I see that Wittgenstein cites Buffon in "Lectures and Conversations on Aesthetics, Psychology, and Religious Belief". Does anyone have a copy of "Lectures and Conversations"? I wonder what Wittgenstein said about Buffon. Similarly for Haldane in A. C. Jackson's notes on Wittgenstein's Cambridge lectures.
As a scientist, it is easy for me to spot people like Buffon who appear both on the list of authors Wittgenstein had read and also in the scientific literature of evolution. As a newbie in philosophy, I need more help identifying those philosophers who were interested in evolution and might have influenced Wittgenstein. Hallett lists Henri Bergson as someone Wittgenstein had read. Bergson wrote, "An identical process {evolutionary?} must have cut out matter {life?} and the intellect {the human mental world?}". Is anyone familiar with Bergson's "Matter and Memory"? Edelman might have used this title for one of his books if Bergson had not already used it!
"The work of the philosopher consists in assembling reminders for a particular purpose." Wittgenstein felt compelled to collect piles of "trivial things" that we all already know, and to endeavor not to leave out a single thing. He sought a "correct" synopsis of all the many trivialities. Why this obsession with detail? This is also how evolution works; when it comes to change, God (or the Devil?) is in the details.
Warning: lengthy biological metaphor:
What is a living organism? A person is determined by about 100,000 genes. Each does a trivial job such as code for the protein hemoglobin, which is the carrier of oxygen in the blood. We can say that a human is the result of 100,000 trivialities. When a mutation occurs in a single gene, what are the evolutionary consequences? You can seldom answer this question just by looking at that one gene. For example, there are several human hemoglobin genes, some are active in the embryo, others in the adult. Other "regulatory proteins" (coded by other genes) bind to the hemoglobin genes and control when each individual hemoglobin gene will be active (used to produce hemoglobin protein) or inactive. In mammals, fetal hemoglobin has a higher affinity for oxygen so that it can grab oxygen from the mother's hemoglobin. Mammals evolved by selecting some mutations in the fetal hemoglobin gene that made it bind oxygen better and other mutations which normally restrict its expression to the human embryo. The "success" of the regulatory mutations only made "sense" with respect to the other genes which specify the proteins (called transcription factors) which interact with the fetal hemoglobin gene and control when it is expressed.
So what is the lesson from biology for philosophy? In order to perform Wittgenstein's type of therapeutic philosophy, you need to know all the trivial details, and all their interactions. Natural selection works by parallel processing....all of the interactions between genes and their specified proteins are tested.......if there is just one failed connection caused by a single point mutation in one gene, the mutant organism can die. The difference between life and death might be one trivial enhancement in the binding of one transcription factor to the fetal hemoglobin gene. If you blink, "if we leave out any [triviality], we still have the feeling that something is wrong".
Wittgenstein wrote, "The answer to every philosophical question is a truism." Darwinism has often been criticized for presenting a truism, a case of circular reasoning, as its most profound truth: "Those organisms which survive are those organisms which have the genes that allow them to survive." People, in thinking about evolution, have been captivated by the idea that evolutionary processes find "solutions". Mammals must get oxygen from the mother's blood to the embryo's blood. Making fetal hemoglobin that can pull oxygen away from the maternal hemoglobin is an "obvious" solution. Wittgenstein continued, "It is just difficult to find THE truism which disposes of the precise thing which troubles me now." Not just any mutation will solve the problem. Make the wrong mutation and fetal hemoglobin will bind oxygen so strongly that it will NEVER release the oxygen it carries, you will have produced a lethal mutation. For Wittgenstein, philosophy could play a selectionistic role, identifying embryonic lethal mutations of thought, lethal mutations that attempt in some way to defy the logic of reality.
"If one tries to advance 'theses' in philosophy, it would never be possible to debate them, because everyone would agree to them." The same "no brainer" complaint is often hurled at Darwinian evolution. I think it was Stephen Gould who coined the phrase "just so stories" to describe the way in which evolutionary biologists concoct rationalizations for the perfect fit of organisms to their environmental niches. "The affinity of fetal hemoglobin was selected by evolution to be greater than that of maternal hemoglobin just so that mammalian embryos could get the oxygen that they need." Such "just so stories" sound so good that evolutionary biologists are seldom bothered with trying to find empirical evidence to support them. Gould has endeavored mightily to argue that not everything in living organisms has been selected for GOOD reasons. Much of life is cobbled together for all the WRONG reasons, it just happens to work GOOD ENOUGH to survive. When something works (like feathers on wings for flying, even if feathers evolved for thermoregulation), who can argue with success?