There are two fundamental problems in science and philosophy. One is whether all the sciences including biology and the neurosciences can be reduced to physics. The other is the nature of our conscious experiences, and their relationships to events in our brains. Are they to be identified with these brain events, being merely an aspect of them as given to the ‘owner’ of the brain? Or have they an independent world of existence, being in correspondence with brain events, or at least some brain events?

The program of the radical materialists is to reduce all sciences to physics and to reduce conscious experiences to the science of brain states and hence to physics. Thus everything would be reduced to properties of matter. Their efforts to deny or to ignore conscious experiences have collapsed because of its intrinsic absurdity. Hence materialists, both radical and ‘tender-minded’, accord conscious experiences a ghostly recognition as appendages or properties of brain states.

This has received wide acceptance, not only among philosophers, but also among neuroscientists. In fact one can say that it has a special appeal to neuroscientists because it gives them assurance that the brain states they are investigating are all that matters in the performance of the brain. They can proceed with their scientific investigations on the brain just as on any other material object without having to be bothered with the possibility of disturbance by non-material mental states. In fact all scientists are materialists and reductionists methodologically.

A theory of dualism (body and mind are separate) entails the problem of interaction. How can mental events and brain states interact? The failure of dualists, including myself, to give any precise explanation of the postulated interaction has led to the denial of dualism. My view is that brain science is at too primitive a level to allow more than speculations that cannot be tested adequately. For the same reason there is no satisfactory account of interactionism, yet the denial of interactionism means the denial of free will.

If the reductionists are right, man is no more than a superior animal, entirely a product of the chance and necessity of evolution. His conscious experiences, even those of the most transcendent creative and artistic character, are nothing but the products of special states of the neural machinery of his brain, itself a product of evolution. If the dualists are right, man has in addition a supernatural component, his conscious self. Thus with his spiritual nature he transcends the evolutionary origin of his body and brain.

But at a more mundane level there is a fundamental issue for man. Has he free will or is it an illusion? If the reductionists are right, this cannot be true in reality, only in appearance. Free will is reduced to some brain states bringing about other brain states, which is purely a neurophysiological happening explicable completely in materialist terms.

As I read many philosophical writings I am led to believe that the learned authors must at all costs propose a nice tidy theory. We have to learn to live with problems beyond our present understanding.

I am appalled by the naiveté of concepts and of programs that are suggested, for example the cerebroscope [today: brain scans]. It is pure fantasy that some instrument could provide a meaningful ‘picture’ of the events in a brain at the time of some conscious experience. At a conservative estimate, even for the simplest perception, each of tens of millions of neurons would be engaged in patterns of impulse discharges, the whole ensemble having unimaginable complexities in space and time. In our present understanding meaningful activities occur when clusters, probably of tens or hundreds of neurons, are in collusive operation with discharges above or below the noise level of the incessant background discharges. This pattern in space and time is ‘written’ by sequential synaptic actions of neuron to neuron each stage occupying only about one thousandth of a second. Thus the whole assemblage of neurons engaged in some evolving pattern has a dynamic complexity beyond instrumental display at any time into the foreseeable future. It is time for the cerebroscope [and other instruments for which such claims are made] to be relegated forever to the world of science fiction.