The common acceptance of pleasure and pain as the fundamental sensations, even with Wundt’s addition of the sensations of tension and relaxation, of rest and stimulation, makes the division of psychical phenomena into sensations and perceptions too narrow for due treatment of the vague preliminary stages to which I have referred. I shall go back therefore to the widest classification of psychical phenomena that I know of, that of Avenarius into “elements” and “characters.” The word “character” in this connection, of course, has nothing to do with the subject of characterology. Avenarius added to the difficulty of applying his theories by his use of a practically new terminology (which is certainly most striking and indispensable for some of the new views he expounded). But what stands most in the way of accepting some of his conclusions is his desire to derive his psychology from the physiology of the brain, a physiology which he evolved himself out of his inner consciousness with only a slight general acquaintance with actual biological facts. The psychological, or second part of his “Critique of Pure Experience,” was really the source from which he derived the first or physiological part, with the result that the latter appears to its readers as an account of some discovery in Atlantis. Because of these difficulties I shall give here a short account of the system of Avenarius, as I find it useful for my thesis. An “Element” in the sense of Avenarius represents what the usual psychology terms a perception, or the content of a perception, what Schopenhauer called a presentation, what in England is called an “impression” or “idea,” the “thing,” “fact,” or “object” of ordinary language; and the word is used independently of the presence or absence of a special sense-organ stimulation--a most important and novel addition. In the sense of Avenarius, and for our purpose, it is a matter of indifference to the terminology how far what is called “analysis” takes place, the whole tree may be taken as the “element,” or each single leaf, or each hair, or (where most people would stop), the colours, sizes, weights, temperatures, resistances, and so forth. Still, the analysis may go yet further, and the colour of the leaf may be taken as merely the resultant of its quality, intensity, luminosity, and so forth, these being the elements. Or we may go still further and take modern ultimate conceptions reaching units incapable of sub-division.