It may seem as though, in the present chapter, I had been guilty of an inconsistency in arguing first against determinism and then against free will. But in fact both are absolute metaphysical doctrines, which go beyond what is scientifically ascertainable. The search for causal laws, as we saw, is the essence of science, and therefore, in a purely practical sense, the man of science must always assume determinism as a working hypothesis.
Source: Religion and Science, 1935, chapt. 6
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