Scientific Naturalism: A House Divided?
Abstract: For centuries, philosophical naturalists have claimed that science provides strong epistemic support for their worldview. Many of these naturalists also espouse methodological naturalism, the view that science cannot consider ‘God hypotheses’ but must explain phenomena only by natural causes. For these thinkers philosophical naturalism and methodological naturalism go hand-in-hand.
This essay argues that philosophical naturalists ought to reject methodological naturalism in science. When linked to methodological naturalism, philosophical naturalism actually moves toward a kind of epistemic fundamentalism. Joined with methodological naturalism, philosophical naturalism can never be scientifically disconfirmed but will always be confirmed. ‘God hypotheses,’ on the other hand, can never be scientifically confirmed, yet many philosophical naturalists believe that they can be scientifically disconfirmed. Moreover, when philosophical naturalism is united with methodological naturalism, this dynamic holds regardless of the empirical evidence. For example, the confirmation of philosophical naturalism is guaranteed because methodological naturalism mandates that the only theories considered are naturalistic ones; hence, the theory with the greatest epistemic virtues must be naturalistic—no matter what the empirical evidence is. Thus, the union of philosophical naturalism and methodological naturalism produces a kind of dogmatism in which the ground rules are biased toward philosophical naturalism and empirical evidence is marginalized. The philosophical naturalist has created terms of engagement in which theistic-friendly hypotheses cannot succeed, but are likely to fail. Naturalistic hypotheses, however, cannot fail but must succeed. Heads I win, tails you lose.
This essay recommends that philosophical naturalists avoid dogmatism by adopting a two-tier conception of science: in private they should retain methodological naturalism but in public they should adopt a pluralistic conception of science free from methodological naturalism. This allows philosophical naturalists to pursue a robust (private) naturalistic research program while also having a public science that genuinely considers God hypotheses in the hope of disconfirming them.
From a Christian perspective, the strategy of this essay is to draw philosophical naturalists into a serious scientific dispute with God hypotheses, instead of being dismissive of these hypotheses under the pretense of methodological naturalism. When philosophical naturalists engage God hypotheses, I predict that the scientific case for philosophical naturalism will be attenuated and the overall scientific credibility of theism will be enhanced.