Human beings, like everything else, are part of the natural world. The natural world is all there is. But to say that everything that exists is just part of the one world of nature is not the same as saying that there is just one theory of nature that will describes and explain everything that there is. Reality may be composed of just one kind of stuff and properties of that stuff but we need many different kinds of theories at different levels of description to account for everything there is.
Theories at these different levels may not be reduced one to another. What matters is that they be compatible with one another. The astronomy Newton gave us was a triumph over supernaturalism because it united the mechanics of the sub-lunary world with an account of the heavenly bodies. In a similar way, biology allowed us to advance from a time when we saw life in terms of an elan vital. Today, the biggest challenge is to explain our powers of thinking and imagination, our abilities to represent and report our thoughts: the very means by which we engage in scientific theorising. The final triumph of the natural sciences over supernaturalism will be an account of nature of conscious experience. The cognitive and brain sciences have done much to make that project clearer but we are still a long way from a fully satisfying theory.
But even if we succeed in producing a theory of human thought and reason, of perception, of conscious mental life, compatible with other theories of the natural and biological world, will we relinquish our cherished commonsense conceptions of ourselves as human beings, as selves who know ourselves best, who deliberate and decide freely on what to do and how to live? There is much evidence that we won't. As humans we conceive ourselves as centres of experience, self-knowing and free willing agents. We see ourselves and others as acting on our beliefs, desires, hopes and fears, and has having responsibility for much that we do and all that we say. And even as results in neuroscience begin to show how much more automated, routinised and pre-conscious much of our behaviour is, we are remain unable to let go of the self-beliefs that govern our day to day rationalisings and dealings with others.
We are perhaps incapable of treating others as mere machines, even if that turns out to be what we are. The self-conceptions we have are firmly in place and sustained in spite of our best findings, and it may be a fact about human beings that it will always be so. We are curious and interested in neuroscientists findings and we wonder at them and about their applications to ourselves, but as the great naturalistic philosopher David Hume knew, nature is too strong in us, and it will not let us give up our cherished and familiar ways of thinking for long. Hume knew that however curious an idea and vision of ourselves we entertained in our study, or in the lab, when we returned to the world to dine, make merry with our friends our most natural beliefs and habits returned and banished our stranger thoughts and doubts. It is likely, as this end of the year, that whatever we have learned and whatever we know about the error of our thinkings and about the fictions we maintain, they will still remain the most dominant guiding force in our everyday lives. We may not be comforted by this, but as creatures with minds who know they have minds — perhaps the only minded creatures in nature in this position — we are at least able to understand our own predicament.