For me the most convincing argument against Bryant’s proclamations about metaphysical naturalism as the underlying philosophy of scientific practice is heuristic and historical: much of what is important in science was created by scientists who did not in fact situate themselves in a naturalist paradigm. We can cite Newton, whose inspiration was theological and alchemical, and Wolfgang Pauli, one of the creators of quantum theory, who tried to create a wider paradigm based on combining physics with the Jungian unconscious, but there are many other examples.
Another important objection to this sort of proclamation is that one can be both in favour of pluralism (which Bryant is not) and a defender of naturalism. The pluralism will nuance the naturalism in making it less metaphysical: naturalism is an open research programme and not a fait accompli. Other paradigms can give content to, enrich, extend and complexify the naturalist paradigm; each scientific style of research will have its own naturalism: for example a Newtonian naturalism, if we could amputate the theological substrate from Newton’s general research paradigm, will be different to, and I would argue less satisfying and fecund than, a Machian naturalism, etc.
The epistemologist and sociologist of science Steve Fuller has condemned, in several books, the continuing narcissism of naturalism on the simple ground that many of our most important scientific theories were created by people whose motivation was not naturalistic but religious, mystical, or hermetic. The paradox is that the naturalist worldview if it had been universally espoused would not have led to the discoveries that seem to confirm it.
This is an example of the simple Feyerabendian point that the practice of science contains important elements that are repressed or occulted in the presentation of its results, but that are essential to its progress. Feyerabend himself was very favorable to naturalism, but emphasised that it was untestable if not confronted with rival metaphysical research programs. A further point is that Being cannot be exhausted by any single worldview, and that taking one’s particular worldview as a description the very nature of Being is a form of metaphysical narcissism.
Popper regarded the Darwinian theory of evolution as just such a metaphysical research programme, perhaps producing hypotheses that themselves are testable, but remaining itself in its generality untestable. It is truly amusing to see an attempt to buttress this ontological myth of the triumph of naturalism with an appeal to the an even more dubious metaphysical theory, Freudian psychoanalysis, and the much lauded and blindly repeated edifying tale of psychoanalysis as the “third blow” to our narcissism. The only narcisssism here is Freud’s, when he compares himself (in 1917!) to Copernicus and Darwin. This declaration came soon after Freud learnt that he would not be receiving the Nobel Prize that in his opinion he deserved, so the whole concept of the narcissistic wound is a projection.
Freudian psychoanalysis, that still finds favour with Bryant, is not at all a naturalism. It appeals to non-naturalistic entities such as the “unconscious”, the psyche, the id, the ego, and the superego, that Freud makes no attempt to establish as or anchor in material or natural agencies. The birth of Freudian psychoanalysis lies in a retreat from naturalism, and also from testability. The organisation of the psychoanalytic movement was based on the ruthless imposition of Freud’s narcissistic authority in matters both theoretical and practical. Rival theorists and rival hypotheses were expelled in as humiliating a manner as possible. Freudian psychoanalysis is a paradigm case of narcissistic denial.
This raises the question of the role of the unconscious. Scientism gives it a very reduced role, limiting it to a sort of regional ontology inside a literalist naturalist paradigm. Deleuze and Guattari’s notion of the productive unconscious suggests a very different perspective, where the role of the unconscious is much greater and more pervasive, informing positively all our theories and practices.