Chapter XVII

may serve as a counterpoise to the mind-stuff theory, which says that there are nothing but substantive sensations, and denies the existence of relations of difference between them at all.

[414] Cf. Stumpf, Tonpsychologie, i, 121, and James Ward, Mind, i, 464.

[415] The ordinary treatment of this is to call it the result of the _fusion_ of a lot of sensations, in themselves separate. This is pure mythology, as the sequel will abundantly show.

[416] "We often begin to be dimly aware of a difference in a sensation or group of sensations, before we can assign any definite character to that which differs. Thus we detect a strange or foreign ingredient or flavor in a familiar dish, or of tone in a familiar tune, and yet are wholly unable for a while to say what the intruder is like. Hence perhaps discrimination may be regarded as the earliest and most primordial mode of intellectual activity." (Sully: Outlines of Psychology, p. 142. _Cf._ also G. H. Schneider: Die Unterscheidung, pp. 9-10.)

[417] In cases where the difference is slight, we may need, as previously remarked, to get the dying phase of _n_ as well as of _m_ before _n-different-from-m_ is distinctly felt. In that case the inevitably successive feelings (as far as we can sever what is so continuous) would be four, _m, difference, n, n-different-from-m_. This slight additional complication alters not a whit the essential features of the case.

[418] Analysis. J. S. Mill's ed., ii, 17. Cf. also pp. 12, 14.

[419] There is only one obstacle, and that is our inveterate tendency to believe that where two things or qualities are compared, it _must_ be that exact duplicates of both have got into the mind and have matched themselves against each other there. To which the first reply is the empirical one of "Look into the mind and see." When I recognize a weight which I now lift as _inferior_ to the one I just lifted; when, with my tooth now aching, I perceive the pain to be _less_ intense than it was a minute ago; the two things in the mind which are compared would, by the authors I criticise, be admitted to be an actual sensation and an image in the memory. An image in the memory, by general consent of these same authors, is admitted to be a weaker thing than a sensation. Nevertheless it is in these instances judged stronger; that is, an object supposed to be known only in so far forth as this image represents it, is judged stronger. Ought not this to shake one's belief in the notion of separate representative 'ideas' weighing themselves, or being weighed by the Ego, against each other in the mind? And let it not be said that what makes us judge the felt pain to be weaker than the imagined one of a moment since is our recollection of the _downward nature of the shock of difference_ which we felt as we passed to the present moment from the one before it. That shock does undoubtedly have a different character according as it comes between terms of which the second diminishes or increases; and it may be admitted that in cases Where the past term is doubtfully remembered, the memory of the shock as _plus_ or _minus_, might sometimes enable us to establish a relation which otherwise we should not perceive. But one could hardly expect the memory of this shock to overpower our actual comparison of terms, both of which are _present_ (as are the image and the sensation in the case supposed), and make us judge the weaker one to be the stronger.--And hereupon comes the second reply: Suppose the mind does compare two realities by comparing two ideas of its own which represent them--what is gained? The same mystery is still there. The ideas must still be _known_; and, as the attention in comparing oscillates from one to the other, past must be known with present just as before. If you must end by simply saying that your 'Ego,' whilst _being_ neither the idea of _m_ nor the idea of _n_, yet knows and compares both, why not allow your pulse of thought, which _is_ neither the thing _m_ nor the thing _n_, to know and compare both directly? 'Tis but a question of how to _name_ the facts least artificially. The egoist _explains_ them, by naming them as an Ego 'combining' or 'synthetizing' two ideas, no more than we do by naming them a pulse of thought knowing two facts.

[420] I fear that few will be converted by my words, so obstinately do thinkers of all schools refuse to admit the unmediated function of _knowing a thing_, and so incorrigibly do they substitute _being the thing_ for it. E.g., in the latest utterance of the spiritualistic philosophy (Bowne's Introduction to Psychological Theory, 1887, published only three days before this writing) one of the first sentences which catch my eye is this: "What remembers? The spiritualist says, the soul remembers; it abides across the years and the flow of the body, and _gathering up its past, carries it with it_" (p. 28). Why, for heaven's sake, O Bowne, cannot you say '_knows it_'? If there is anything our soul does _not_ do to its past, it is to carry it with it.

[421] Sensations of Tone, 2d English Ed., p. 65.

[422] Psychology, i, 345.

[423] A Budget of Paradoxes, p. 380.

[424] The explanation I offer presupposes that a difference too faint to have any direct effect in the way of making the mind notice it _per se_ will nevertheless be strong enough to keep its 'terms' from calling up identical associates. It seems probable from many observations that this is the case. All the facts of 'unconscious' inference are proofs of it. We say a painting 'looks' like the work of a certain artist, though we cannot name the characteristic differentiæ. We see by a man's face that he is sincere, though we can give no definite reason for our faith. The facts of sense-perception quoted from Helmholtz a few pages below will be additional examples. Here is another good one, though it will perhaps be easier understood after reading the chapter on Space-perception than now. Take two stereoscopic slides and represent on each half-slide a pair of spots, _a_ and _b_, but make their distances such that the _a_'s are equidistant on both slides, whilst the _b_'s are nearer together on slide 1 than on slide 2. Make moreover the distance _ab = ab'''_ and the distance _ab' = ab''_. Then look successively at the two slides stereoscopically, so that the _a_'s in both are directly fixated (that is fall on the two foveæ, or centres of distinctest vision). The _a_'s will then appear single, and so probably will the _b_'s. But the now single-seeming _b_ on slide 1 will look nearer, whilst that on slide 2 will look farther than the _a_. But, if the diagrams are rightly drawn, _b_ and _b'''_ must affect 'identical' spots, spots equally far to the right of the fovea, _b_ in the left eye and _b'''_ in the right eye. The same is true of _b'_ and _b''_. Identical spots are spots whose sensations cannot possibly be discriminated as such. Since in these two observations, however, they give rise to such opposite perceptions of distance, and prompt such opposite tendencies to movement (since in slide 1 we _converge_ in looking from _a_ to _b_, whilst in slide 2 we _diverge_), it follows that two processes which occasion feelings quite indistinguishable to direct consciousness may nevertheless be each allied with disparate associates both of a sensorial and of a motor kind. Cf. Donders, Archiv f. Ophthalmologie, Bd. 13 (1867). The basis of his essay is that we cannot _feel_ on which eye any particular element of a compound picture falls, but its effects on our total perception differ in the two eyes.

_a b_ _a b'_

_Slide_ 1. . . . .

_a b''_ _a b'''_ _Slide_ 2. . . . .

[425] A. W. Volkmann: Ueber den Einfluss der Uebung, etc., Leipzig Berichte, Math.-phys. Classe. x, 1858, p. 67.

[426] _Ibid._ Tabelle 1, p. 43.

[427] Professor Lipps accounts for the tactile discrimination of the blind in a way which (divested of its 'mythological' assumptions) seems to me essentially to agree with this. Stronger ideas are supposed to raise weaker ones over the threshold of consciousness by fusing with them, the tendency to fuse being proportional to the similarity of the ideas _Cf._ Grundtatsachen, etc., pp. 232-3; also pp. 118, 492, 526-7.

[428] Sensations of Tone, 2d. English Edition, p. 62.

[429] Compare as to this, however, what I said above,