The psychophysical harmony argument contends that the remarkable correlation between mental states and physical states in conscious beings points to an underlying divine coordination or design. The argument's inferential structure moves from the observation of systematic correspondences between subjective experiences and neural processes, through the improbability of such precise correlations arising by chance or natural selection alone, to the conclusion that a transcendent intelligence best explains this harmony. Unlike mere mind-body interaction puzzles, this argument specifically focuses on the fine-tuned nature of psychophysical laws that enable consciousness to emerge from and interact meaningfully with physical substrates. The argument claims that naturalistic explanations fail to account for why physical processes should give rise to subjective experience at all, and more importantly, why the resulting experiences should be so exquisitely matched to survival needs and environmental features.
The modern formulation of this argument emerged from Leibniz's pre-established harmony doctrine, though focused specifically on consciousness rather than general metaphysics. William James in The Varieties of Religious Experience (1902) noted the mysterious fit between mental life and biological function. C.D. Broad in The Mind and Its Place in Nature (1925) systematically explored psychophysical correlations as pointing beyond naturalism. Contemporary defenders include Richard Swinburne in The Existence of God (2004), who argues that theism better explains psychophysical laws than materialism, and Robin Collins in The Blackwell Companion to Natural Theology (2009), who develops a fine-tuning argument specifically for consciousness. J.P. Moreland in Consciousness and the Existence of God (2008) argues that the precise calibration of psychophysical connections requires intentional design. Alvin Plantinga has incorporated psychophysical harmony into his evolutionary argument against naturalism, suggesting that reliable cognitive faculties emerging from evolution would be miraculous without divine guidance.
Critics argue that evolutionary biology adequately explains psychophysical correlations through adaptive advantage, with Daniel Dennett in Consciousness Explained (1991) proposing that apparent harmony results from selection pressures favoring organisms whose mental states track reality. Patricia Churchland in Neurophilosophy (1986) contends that co-evolution of brain and mind makes correlation unsurprising. Defenders respond that evolution presupposes rather than explains the existence of psychophysical laws enabling consciousness to emerge from matter. They argue that natural selection can only work with pre-existing psychophysical connections, not create them ex nihilo. The anthropic principle objection—that we observe harmony simply because inharmonious universes wouldn't produce observers—is countered by noting that this doesn't explain why any universe should permit psychophysical harmony at all. Proponents maintain that the sheer existence of lawlike connections between qualitatively distinct domains (mental and physical) remains deeply puzzling under naturalism.
This formulation differs from the hard problem of consciousness by focusing on harmonious correlation rather than the mere existence of qualia. Unlike the emergence problem, which questions how consciousness arises from non-conscious components, psychophysical harmony emphasizes the suspiciously beneficial nature of mind-brain connections. The intentionality argument concerns the aboutness of mental states, while psychophysical harmony addresses the broader question of why mental and physical realms interact so fruitfully. Unlike classical mind-body dualism arguments, this formulation doesn't require substance dualism but only the recognition of apparently designed correlations between mental and physical domains.