Naturalism as a Metaphysical Perspective
Western philosophers since Descartes have typically found themselves within a world of conscious experience as the ultimate ground of epistemological and metaphysical inquiry. But, if it is the case that we find ourselves in a world of conscious experience, then how can we ever hope to build a foundation for knowledge? We have no way of stepping out of our own consciousness to survey the relations between it and the rest of reality. We are indeed trapped within consciousness. This position is supported by standard modern neuroscience explanations, in which we are “brains in vats”: consciousness is caused by the brain, and whatever contact we have with the world is mediated through signals that make it to the brain only by first going through a transduction to nerve signals at the sensory periphery. Our brains literally float inside our skulls in cerebrospinal fluid and, from the perspective of neuroscience, conscious experience is all about what goes on inside this biological vat. Yet this sort of neuroscientific naturalism takes a lot for granted. It takes for granted a realist picture of reality and, philosophically speaking, this assumption of realism cannot be proven true. This does not mean that we ought to abandon realism or science, but we ought to realize, as Hume and Kant did, the limits of human reason so we can put realism and science in perspective. Let us revisit some of the thoughts of Hume and Kant to see how they arguably undermined any proof of naive realism.