In recent decades, some have argued that developments in science and philosophy have dealt a significant blow to materialism, or more precisely contemporary physicalism: the view that everything that exists is physical, or at least depends on the physical. Patrick Glynn, in his book "God: The Evidence," argues that twentieth-century developments placed serious pressure on the older materialist worldview. In particular, he points to the hard problem of consciousness, the measurement problem and interpretation of quantum mechanics, and the mixed record of reductive scientific programs. These are real philosophical pressure points, especially for simple or reductionist forms of materialism. But the stronger claim that materialism has "collapsed" is an overstatement. The more careful question is whether these problems defeat all serious forms of physicalism, or whether they instead force physicalists to refine their theories.
The Hard Problem of Consciousness
David Chalmers famously articulated the "hard problem" of consciousness. His point is not merely that neuroscience has not yet mapped every neural correlate of experience. Rather, even if we had a complete account of brain mechanisms, perception, reportability, attention, memory, and behavior, there would still seem to be a further question: why should any of those physical and functional processes be accompanied by first-person experience at all? Why is there something it is like to see red or feel pain? This explanatory gap has led many philosophers to doubt that a purely reductive materialist account of consciousness is sufficient.
While the hard problem is a significant challenge, it does not by itself invalidate every form of materialism, still less does it prove theism. Serious physicalist responses include identity theories, functionalist accounts, representational theories, higher-order theories, illusionism, and non-reductive or emergentist versions of physicalism. Some philosophers argue that the gap is epistemic: our current concepts make consciousness seem irreducible even though it is ultimately physical. Others argue that consciousness requires new fundamental principles, as Chalmers himself suggests in forms of naturalistic property dualism. The honest conclusion is therefore limited but important: consciousness remains one of the strongest objections to reductive materialism, but its final metaphysical implications remain disputed.
Quantum Mechanics and Materialism
Quantum mechanics has long been a source of philosophical intrigue because it raises deep questions about measurement, probability, locality, and the relation between observation and physical reality. Some figures, especially in the tradition associated with von Neumann and Wigner, entertained the idea that consciousness might play a role in measurement. However, it would be misleading to identify that view with quantum mechanics as such, or even with the standard Copenhagen family of interpretations in a simple way. The measurement problem is real, but a consciousness-based solution is only one minority proposal among many.
There is no settled consensus among physicists and philosophers of physics about the correct interpretation of quantum mechanics. Many physicists work instrumentally with the formalism without taking a firm metaphysical position; others defend Copenhagen-like approaches, Many-Worlds, de Broglie-Bohm pilot-wave theory, objective-collapse theories, relational interpretations, QBism, or other views. Importantly, most of these interpretations do not require consciousness to collapse the wave function or to complete physical reality. Quantum mechanics may challenge a naive picture of matter as tiny classical billiard balls, but it does not by itself refute physicalism or establish a non-material mind.
Reductive Programs and Their Success
The twentieth century witnessed ambitious attempts to explain complex phenomena in terms of simpler and more fundamental physical processes. There have been major successes, such as the statistical-mechanical explanation of many thermodynamic laws, though even that case involves philosophical complications about probability, irreversibility, and the thermodynamic limit. In biology and psychology, simple reductionist programs have often had to give way to multi-level explanations involving function, information, development, ecology, computation, and social context. This does not show that living beings or minds are non-physical, but it does show that explanation in science is not always a matter of straightforward reduction to lower-level physics.
Despite these challenges, scientific inquiry is usually guided by methodological naturalism: researchers seek law-governed, testable explanations without appealing to supernatural agency within the scientific model. That method should not be confused with the metaphysical thesis that only the physical exists. Researchers often pursue reductive explanations as part of a larger toolkit, while also recognizing that some phenomena require higher-level models or new theoretical frameworks. The mixed success of reductive programs therefore does not imply the collapse of materialism; it more modestly shows that physicalists need not be crude reductionists.
Materialism in Contemporary Philosophy
Despite the challenges outlined above, materialism, or physicalism, remains one of the leading positions in academic philosophy of mind. The PhilPapers surveys have found that just over half of surveyed philosophers accept or lean toward physicalism about the mind, while a substantial minority accept or lean toward non-physicalism and others remain undecided or choose alternative options. So physicalism is not a collapsed view, but neither is it an uncontested consensus.
It is crucial to distinguish between confident mid-century reductionism, which may have been overly optimistic, and the broader range of physicalist positions defended today. Contemporary physicalists may be reductive identity theorists, functionalists, non-reductive physicalists, emergentists, representationalists, or illusionists about phenomenal consciousness. These views differ sharply from one another, but they share the conviction that mental reality is ultimately grounded in the physical order. A fair critique of materialism must address these stronger versions, not only the older slogan that the mind is "nothing but" matter in motion.
Conclusion
In conclusion, the hard problem of consciousness, the interpretation of quantum mechanics, and the mixed success of reductive programs present genuine challenges, especially for simple reductive materialism. But they do not amount to a demonstrated collapse of materialism as such. Nor does the existence of unsolved problems in physicalist theories automatically establish theism; that would be a separate argument. The more balanced verdict is that materialism remains a powerful and widely defended framework, while facing serious unresolved questions that prevent it from being treated as philosophically settled.