Russell, Bertrand. The Scientific Outlook. London: George Allen & Unwin Ltd., 1954 (based on 2nd ed., 1949; 1st ed, 1931).
In Chapter 4, "Scientific Metaphysics", Russell notes that science is losing confidence in itself, in its grip on objective reality, hastened by the conundrums of the new physics. Russell is unhappy with Arthur Eddington's account of physics and thinks his prediction of the ultimate death of the universe will undermine faith in science, belying Eddington's optimistic tone. Russell himself is possessed by a skepticism that denies the unity and lawfulness of the universe. This development is welcomed by partisans of religion. Russell finds a bifurcation in two notions of science, one as metaphysics, the other as practical utility. Practically, science is advancing even while faith in its metaphysical foundations is weakening. Russell has his own doubts about the reality of the external world, but what is not justified is the retreat to religion on the part of James Jeans. The former quasi-religious status of scientists as a priesthood of religion is giving way to a new timidity on the part of scientists.
Chapter 5 directly addresses the question of "Science and Religion". Scientists themselves are returning to religion in face of World War I and the Russian Revolution. Russell dismantles attempts to link quantum mechanics to the rehabilitation of free will. Eddington, for example, is guilty of this. Jeans, on the other hand, argues that God is a mathematician. Russell makes short shrift of this notion and ultimately finds it a rehash of old theological arguments, which do not pass muster from the standpoint of the fundamentally naturalistic basis of science. Russell also has a few words to say about Lloyd Morgan's idealistic notion of emergent evolution.
Russell's own indulgence in skepticism--although briefly in these two chapters--does not significantly detract from his demolition of the merger of science, religion, mysticism, and idealism, perpetrated by scientists themselves. We should also remember that Russell's erstwhile colleague Alfred North Whitehead, author of process philosophy, also took up the cudgels of idealistic metaphysics. (Not a word is said about Whitehead in this book, though I think we know what Russell thought.) This development shows up the ineluctable duality of bourgeois thought, as it vacillates between positivism and irrationalism. World War I was indeed a watershed, which generated a peak in the merger of science and mysticism among the intelligentsia in the 1920s. Yet this was minuscule compared to what followed in the wake of World War II, with the explosion of New Age thought, beginning with the Beats, then the counterculture of the '60s and '70s, and finally the yuppification of the New Age bringing it back to where it belongs among the affluent, the privileged, and the comfortable.