To Miss Grace Norton.

July 14, 1874.

I fear the “conversational essay” will have to wait on conscience, too; for, in my thoughts about it lately, I have been going on with my speculative researches or theorizings in my head, not liking to arrest their growth by putting them prematurely in any form on paper; but “mewing their mighty youth and kindling their undazzled eyes at the full mid-day beams” of crucial tests and facts. Having settled several questions of physiological optics to my satisfaction, the last being “why colors exist,” which includes in its answer why the delight in them exists, instead of giving this delight as the answer (a very subtile teleology, you see, — I hope you won’t condemn it as “ingenious,” as the unconvinced do), I have taken up another subtile question, to which the various momenta of my theories have led up; namely, how touch and sight alone, without the muscular sense, or how the nerves of the skin and the retinas alone, give a perception of space, as I am convinced they do. This conviction came after the explanation; for I had previously believed, with most of the German and English physiologists, that tactual sensations, including the retinal, give only associated “local signs,” without giving any idea, or any essential constituent of the idea of extension in objects. I was led, without making any hypotheses that were not probable antecedently and applicable to previous questions, to an explanation of how tactual impressions may be perceived immediately as more or less distant from one another; that is, independently of the changes consequent on muscular movements, or independently of the muscular sense, as well as of their own proper qualities and intensities. This explanation is very far from going back to that ignorant assumption of absolute simplicity, or immediacy in the perception of space or extension, which some metaphysicians have

made in the teeth of physiological facts. I take, however, a shorter physiological road, and one that leads to a more immediate relation of tactual sensation to the perception of extension than that of local signs associated with movements. The effect of attention moving over a tactile surface, or from nerve to nerve in it, or the cerebral incitement or quantity of innervation produced by attention, gives a physiological datum in the perception of extension which has not been, so far as I know, yet taken account of. I do not consider it a merit of the theory in which I take account of this new quantity as an element in space-perception, that it seems to accord with common sense more nearly than the older one, for common sense is stupid in this matter. A power of trained imagination is indispensable in this most difficult subject, or an understanding which can not only emancipate itself from the stress of sense, but can even turn round and subjugate sense combinations to its analysis, or see how we see, without visualizing and thus duplicating the process.

There is endless confusion, it seems to me, in the still more abstruse questions of metaphysics about object and subject in perception, on account of the lack in thinkers of that analytic imagination, or abstractive understanding, which can possess itself of the dissolved yet distinguished elements, instead of the broken pieces, of sensuous images, and can put them together chemically, so to speak; or can take up a movement in perception as it individually exists, dissecting it out both from what causes it and from what follows it. I wonder whether you get any adequate idea from this most inadequate sentence, or are duly impressed by it with the difficulty of exposition I shall have to contend with in setting forth my theories.

Science has compelled psychologists to the so-called empirical theory of perception, but has not yet, for the most part, trained their imaginations to the adequate comprehension of empirical idealism, to which I believe they will have to come.

Idealism is a “discipline,” rather than a theory; or is true only to an understanding subtile enough not to grossly suppose an external world to be demonstrated, or the question of its nature in any way affected, by striking the ground with a walking-stick. But this theory is in need of a little clearing up as it stands. Its positions are somewhat dislocated, from its contest with metaphysics. It has hitherto made too emphatic its incidental opposition to metaphysical substance in matter, and has become itself metaphysical by positing a substance of consciousness. Empiricism has driven philosophy from both these positions. The real and essential battle of idealism is then against the transference, of the introspective duality, or distinction of subject and object in consciousness, to the line of physical causation in perception; or is against the confusion of the physical conditions of perception with the object of it, and of the psychical conditions with the subject as introspectively distinguished.

About this time last summer, I discussed with Professor Wyman the substitution of new terms in physiology for the metaphysically confused terms, “subject” and “object;” proposing to call what depends in consciousness on internal conditions “encephalic,” instead of subjective, and what depends on external ones “eccephalic.” I held that an hallucination is objective, though encephalic, and that its illusory character does not make it a subjective phenomenon, or an imagination, as is sometimes supposed. The accidental or afterimages of vision, and other illusory appearances, are sometimes called by English writers “subjective,” by a still cruder use of these vague words. The true and false in judgment, or the real and unreal in consciousness, is not a distinction coincident with the introspective division of mental states into subjective and objective. One may either truly or falsely remember and imagine, and either truly or falsely perceive and act. The true and the false, or the real and unreal, of waking

and dreaming, are not the two worlds (as they are somewhat poetically called) of the duplicate or reflective consciousness. Although it is proved by all experience that an objective phenomenon of encephalic origin, like a dream, is illusory, yet this is not an identical proposition, or its truth is not involved in the meaning of its terms. That subjective phenomena are all encephalic is empirically known; and the converse of the proposition, or that all encephalic is subjective, is not true.

The aid I hope to get from the form of the conversational essay is, of course, the motive I have for turning dramatist. But this form brings its own peculiar difficulties, which is the reason, I suspect, why it is not more often used. All that I have put on paper are certain headings of subjects. The dramatic arrangements are still in the shell, while the main themes are some of them still moulting. But do not suppose that I shall send you these lucubrations as substitutes for letters. I shall probably write long prefaces to each part in way of letters, as authors always do, making a great flutter about the new-fledged things, gratulations that they have survived the dangers of callow youth, and deprecations of injurious criticisms.