Abstract
Nevertheless, despite whatever optimism about the future unification of sciences is justified, there are now, as there have been for centuries, difficult problems confronting the materialist. Perhaps the crucial problem concerns the status of sensations, a problem clearly evident as far back as Hobbes who said that sense is "some internal motion in the sentient, generated by some internal motion, of the parts of the object, and propagated through all the media to the innermost part of the organ." Here Hobbes reduces sense to physical motion. But he is also found to say that sense is not motion, but "in all cases, is nothing else but original fancy," or, he says elsewhere, "phantasms" caused by internal motions. He is then directly faced with the problem of reconciling appearances and sensations with his avowed materialism. Neither Hobbes nor any one else has solved this problem, although there have recently been some novel and instructive attempts to do so.