Probably for historical reasons of language and education, it comes naturally to the simple man of today to think of a dualistic relationship between mind and matter as an extremely obvious idea. He finds no difficulty in thinking that we first, through our will, move parts of our living selves, and then, by means of them, move other material things; nor that material things, coming in contact with our bodies, give rise through the nerves to the feeling of touch; that vibrations in the air, when they reach the ear, cause the sensation of sound, and that light, striking the eye, causes that of sight, and so on (meaning that similar things apply to sensations of smell, taste and temperature). But a more careful consideration should make us less ready to admit this interaction of events in two different spheres—if they really are different spheres; for the first (the causal determination of matter by mind) would necessarily have to disrupt the autonomy of material events, while the second (causal influence on mind of bodies or their equivalent, for example, light) is absolutely unintelligible to us; in short, we simply cannot see how material events can be transformed into sensation or thought, however many text books, in defiance of Du Bois Reymond, go on talking nonsense on the subject.