This is the clearest analysis I have seen:
This is good too (http://www.fritzwagn...f_contents.html)
On Biological Phenomenalism and Charles Darwin
[. . . The] success of the theory of evolution in the nineteenth century [ is a source of bewilderment to the historian of ideas]. The evolution of the forms of life, as we observed [earlier in the text], was treated thoroughly in the biological theory of the eighteenth century. The creational theory of the species was abandoned; the idea of a chronological succession of living forms from primitive to the most complicated was conceived. The increase of phenomenal knowledge concerning their unfolding was acknowledged, but the insight was also gained that the idea of an evolution of living forms did not bring us one step nearer to an understanding of the mystery of the substance that was evolving through the chain of forms.
The chain of evolutionary forms as a whole was just as much of an ultimate datum in ontology as previously had been the single species. No speculative prolongation of the chain into inorganic matter and no raising of the question of whether organic forms originated in inorganic matter could change the problem either. Such speculation simply meant pushing the mystery of the potentiality that unfolded morphologically in time a step further back without understanding it any better. . . . By the time of Kant the problem of evolution was reduced to its phenomenal proportions.
And now, in the nineteenth century, as if nothing had happened, a new phenomenal theory of evolution, operating with the conceptions of the struggle for life, the survival of the fittest, natural selections, etc., had a popular success and became a mass creed for the semieducated. A theory that, assuming that it was empirically tenable, could at best furnish an insight into the mechanics of evolution without touching its substance was accepted as a revelation concerning the nature of life and as compelling a reorientation of our views concerning the nature of man and his position in the cosmos.
. . . . A theory that in itself might contribute to our knowledge of the phenomenal unfolding of a substance is perverted into a philosophy of substance; the causal relationship of phenomena (always assuming the correctness of the theory) is understood as an explanation on the level of the substance of life.
The principal causes of this transformation of phenomenal relations into a phenomenal reality are well known. Darwin was a great empirical biologist who marshaled convincingly the materials in support of his theory; the massiveness of empirical data opened a view into a new realm of ordered knowledge. At the same time, neither Darwin nor his followers were the best of theorists, so that the issue between phenomenal and substantial knowledge could remain relatively obscure. We are faced with the problem of the nineteenth century that with the increasing specialization of the sciences, scholars who are impeccable as masters of their field become unable to see the theoretical problems of their special science in proper relation to the problems of ontology and metaphysics.
Moreover, the will to create a phenomenal reality out of the propositions of a science of phenomena was an independent factor on the occasion of the magnificent unfolding of biology, just as it was on the occasion of the unfolding of astronomy and physics in the seventeenth century.
The evolutionary movement has a distinct anti-Christian, secularistic flavor through the assumption that the interpretation of man as the final link in the chain of evolution has a bearing on the understanding of man as a spiritual existence; the will to understand man as having his position in a world-immanent order revealed by a science of phenomena, instead of in a transcendental order revealed by the cognitio fidei, is the dynamic factor in the transformation.
The biological conceptions of the struggle for life, the survival of the fittest, etc., were absorbed into the interpretation of society and politics. Within the order of competitive society the idea of natural selection could fortify the belief that the successful man is the better man, that success is fated in the order of nature, and that the order created by success is a right order because it is willed by nature—irrespective of the moral and spiritual issues involved. . . . [T]he substance of man and society is overlaid with a coat of biological phenomena that smothers the spiritual and moral awareness and tends to replace the spiritual order of society with an order of biological survival . . . .