The difference between Professor Mach's view and mine may appear greater than it is, because the problem which Professor Mach treats in his article "The Analysis of the Sensations," lies in quite a different field from that of the problem of the relation of feeling to motion. The problem being different, the same and similar terms are not only used for different purposes, but demand also different comparisons. Professor Mach's symbols A B C … and α β γ … represent a contrast different from that of feeling and motion. They represent the contrast of sensations and thoughts. Sensations, such as green and hard, are colors, pressures, tastes, etc; thoughts are memory-images, concepts, volitions, etc.
Professor Mach says: "How the representative percepts of imagination and memory are connected with sensations, what relations they bear to them, as to this I dare venture no opinion…. Monism, as yet, I cannot thoroughly follow out; because I am lacking in clearness with regard to the relation of α β γ … to A B C …; but I believe that the first step towards a competent monism lies in the assertion that the same A B C … are both physical and psychical elements."
My symbols A B C … and α β γ … represent the contrast of physical and psychical elements, not of sensations and thoughts. Concerning thoughts, Professor Mach says he is much inclined to co-ordinate them with sensations so that his Greek symbols might differ from his Italic symbols not otherwise than the latter, viz. A B C …; differ among themselves. Taking this ground, I believe, it would be preferable to symbolise them accordingly among the Italic letters, perhaps as X Y Z. In the diagrams on page 407 they are called Μμ, Νν, Σς.
#Feeling, sense-impression and sensation defined.#
According to my terminology, feeling, as explained above, is the most general term expressing any kind and degree of subjective awareness. A sense-impression is a single irritation of one of the senses, the irritation being a special kind of motion plus a special and correspondent kind of feeling. A sensation is a sense-impression that has by repetition acquired meaning. A later sense-impression, when felt to be the same in kind as a former sense-impression, constitutes, be it ever so dimly, an awareness of having to deal with the same kind of cause of a sense-impression; thus giving meaning to it. By sensation, accordingly, I understand a sense-impression which has acquired meaning. And feelings that have acquired meaning, I should call mental states. Representative feelings (feelings that have a meaning) are the elements of mind.
#Thought and thinking defined.#
By thinking I understand the interaction that takes place between representative feelings. Such are the comparisons of sensations with memory-pictures, or of memory-pictures among themselves, the experimenting with memory-pictures so as to plan new combinations, etc. The products of thinking are called thoughts; and by thought in the narrower sense is commonly understood abstract thought which on earth is the exclusive privilege of man.
If I am not mistaken Professor Mach understands by sensations (represented by him as A B C …) what I should call sense-impressions; while thoughts, memories, and volitions (represented by him as α β γ …) form what I should call mind, or all kinds of mental states, that is, the domain of representations.
The higher spheres of thought, or representative feelings, grow out of and upon the lower spheres. Sense-impressions, as I have attempted to explain in the article "The Origin of Mind" (The Monist, No. 1), are the data which are worked out into concepts and ideas; they are the basis upon which the whole structure of mind rests. The reflex motions of simple irritations, being modified in higher spheres by the rich material of experience consisting of memory-images, and by the possibility of forethought created through experience, become volitions.
#Monism and the origin of mind.#