Contradictions of naturalism

Mary Midgley

Several times I have pointed out some of the contradictions stated by naturalist philosophy and its different variants: materialism, reductionism, physicalism, scientism, etc. In the previous post I pointed out that Raymond Tallis has detected two important contradictions that he calls darwinitis and neuromania. In this post I am going to bring together a few more, because when one sees them together their power is multiplied. Here are those I have selected:

• Science is the only valid source of human knowledge: Which science has reached this conclusion? Physics? Biology? None of the sciences. Therefore, if what this statement says is true, this statement must be false. We arrive at a contradiction. On the other hand, if this statement is false, there is no problem. Ergo, this statement is false. Therefore, scientism (and thus naturalism) is false.

The end of the selfish gene

The German biologist August Weismann (1834-1914) was one of the most influential biologists of the late nineteenth century. His most important contribution was the theory of germinal plasma, also called in his honor Weismannism. According to this theory, there are two classes of cells in all multi-cellular living organisms (see Figure 1):

Figure 1

• Somatic cells, represented in the figure by an S, that make up most of the body and do not play any role in inheritance.
• Germ cells, represented in the figure by a G: the gametes, ovules and sperm, which pass the genetic information to the next generation.

Epigenesis and epigenetics

Fertilization of the egg by the sperm

In the previous post we saw that at the beginning of the 19th century the theory of epigenesis seemed to have won the game. However, after 1850, and for just over a century, a cascade of new discoveries tipped again the balance towards the theory of preformation. Let us see what they were:

1. The existence of a nucleus within animal and plant cells.
2. The confirmation that the nuclei of the male and female gametes are fused during fertilization. This put an end to spermism and ovism and made it clear that the new being begins in the zygote.
3. The confirmation that certain structures (the chromosomes) appear during cell reproduction inside the nucleus of the cell, which seem to play a very important role. It was also found that in the chromosomal endowment of the zygote, half of the chromosomes come from the father and the other half from the mother.
4. A new science (Genetics) was originated in the experiments of Thomas Hunt Morgan, who showed that the chromosomes are linked to Mendelian inheritance.
5. The works of Oswald Avery, who showed that DNA, a nucleic acid that appears in chromosomes, is the basis of Mendelian inheritance.
6. The discovery of the structure of DNA (a double helix), made in the early 1950’s by Francis Crick, James Watson and Rosalind Franklin.
7. The deciphering of the genetic code, which took place during the 1950s and the 1960s.