THE NATURE OF SENSATIONS

Sensations are the mental ultimates of the psychological universe just as the chemical elements are the ultimates of the chemical universe. Sensations are the colors that we see—the reds and greens and purples and blacks and whites and greys; the tactual experiences that we feel—the warmths and colds and tickles and pains and aches; the tones and noises that we hear; all the vast number of odors that we smell and our few simple tastes of salt, sweet, sour and bitter. Of course these simple experiences very seldom appear isolated. They come to us as integral parts of much more complex experiences, as the taste of lemonade, the smell of a flower or the colors of a landscape. In this they parallel the elements of the other sciences which must be separated out, artificially if necessary, before they can be adequately studied.

It is a little ironical that at the very time Kant was denying that any mental phenomena could ever be treated mathematically the psychologists, themselves, were bringing the facts of sensation under mathematical laws and the natural scientists were accepting these laws as scientific, for it is to be assumed that biologists and physicists might be more jealous of the limits of an exact science than philosophers. The natural scientists, however, did more than complacently accept the psychologists’ own investigations of sensations; they verified and extended them and pointed out new fields for the psychologists to explore. This was, of course, no mere altruistic gesture. Natural scientists, themselves, have a real and pertinent interest in all sensory problems and it is in their solution that we come to understand the relations between the three sciences of physics, biology and psychology, the differences among them and their interdependence on one another.