There is a deeper problem with extending the materialistic understanding of nature to human beings. For starters, we experience the outside world—the world described by the laws of physics and chemistry—very differently than we experience ourselves. This is a point emphasized by philosopher Arthur Schopenhauer. All other things we experience indirectly, from the outside, through the apparatus of our senses, but ourselves we experience directly, from the inside, without the involvement of our senses. Only about ourselves do we have this kind of “inside information,” which is the clearest, most fundamental knowledge we can have. Based on this privileged and unique access, we know that the external account of reality, however accurate it may be in describingraindrops and cheetahs, is not the full story when it comes to describing ourselves.

We are sure, for example, that we exist. David Hume said that we can’t really even know this: “When I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hate, pain or pleasure. I never can catch myself at any time without a perception and never can observe any thing but the perception. Consequently, for Hume, the self is a fiction because it cannot be empirically located. But the remarkable thing is that we are conscious of our own existence prior to having any feelings and thoughts. Besides, our feelings and thoughts are experi- enced as “possessions” somehow distinct from the self, while the self is experienced directly. Schopenhauer writes that as we are the subjects of our own inquiry, the materialist mistake is that of “the subject that forgets to take account of itself.” Hume is observing sensations while ignoring the fact that he is the one who is doing the observing. He is allowing his indirect knowledge of external phenomena to trump his direct knowledge of the “I” that is having these experiences.