As Engels notes, science could only, at that that time, hypothesise that such organic life comes into existence as a result of such chemical reactions. Duhring, however, posited “independent coexistence of products of nature unmediated by descent.” (p 91)
How could these have arisen?
“... if these homogeneous products of nature — organic, of course, as here we are only dealing with such — are not connected by descent, they or each of their ancestors must have been put into the world by a separate act of creation at the point “where the thread of descent breaks off”,. So we arrive once again at a creator and at what is called deism.” (p 92)
Engels notes that Duhring mistakenly ascribes to Darwin the claim that the origin of variations is sex, whereas Darwin only ascribes the preservation of variations to sex, i.e. heredity. He also notes the development of the sciences of embryology and palaeontology, whose discoveries had further confirmed Darwin's theory.
“There is in fact a peculiar agreement between the gradual development of organic embryonic germs into mature organisms and the sequence of plants and animals succeeding each other in the history of the earth. And it is precisely this agreement which has given the theory of evolution its most secure basis.” (p 93)
By contrast, Duhring is forced to acknowledge the existence of such variability, but posits it alongside and separate from independent, unchanging products of Nature.
He says,
“The ... variability of species is an acceptable assumption”. But in addition “the independent coexistence of homogeneous products of nature, unmediated by descent” is valid too. (p 93)
So, after all, Duhring has to accept the Darwinian theory, and yet, even then he claims it to be a secondary factor.
“... after all his moral indignation over the struggle for existence through which natural selection operates we suddenly read:
“The deeper basis of the constitution of creatures is thus to be sought in the conditions of life and cosmic relations, while the natural selection emphasised by Darwin can only come in as a secondary factor”” (p 94)
Finally, Duhring takes issue with the term metamorphosis, proposing instead the term composition. Metamorphosis, of course, implies organic development from within, whereas composition implies a conscious process, guided from without.
No comments:
Post a Comment