VI. The Conterminousness of Different Minds

With transition and prospect thus enthroned in pure experience, it is impossible to subscribe to the idealism of the English school. Radical empiricism has, in fact, more affinities with natural realism than with the views of Berkeley or of Mill, and this can be easily shown.

For the Berkeleyan school, ideas (the verbal equivalent of what I term experiences) are discontinuous. The content of each is wholly immanent, and there are no transitions with which they are consubstantial and through which their beings may unite. Your Memorial Hall and mine, even when both are percepts, are wholly out of connection with each other. Our lives are a congeries of solipsisms, out of which in strict logic only a God could compose a universe even of discourse. No dynamic currents run between my objects and your objects. Never can our minds meet in the same.

The incredibility of such a philosophy is flagrant. It is 'cold, strained, and unnatural' in a supreme degree; and it may be doubted whether even Berkeley himself, who took it so religiously, really believed, when walking through the streets of London, that his spirit and the spirits of his fellow wayfarers had absolutely different towns in view.

To me the decisive reason in favor of our minds meeting in some common objects at least is that, unless I make that supposition, I have no motive for assuming that your mind exists at all. Why do I postulate your mind? Because I see your body acting in a certain way. Its gestures, facial movements, words and conduct generally, are 'expressive,' so I deem it actuated as my own is, by an inner life like mine. This argument from analogy is my reason, whether an instinctive belief runs before it or not. But what is 'your body' here but a percept in my field? It is only as animating that object, my object, that I have any occasion to think of you at all. If the body that you actuate be not the very body that I see there, but some duplicate body of your own with which that has nothing to do, we belong to different universes, you and I, and for me to speak of you is folly. Myriads of such universes even now may coexist, irrelevant to one another; my concern is solely with the universe with which my own life is connected.

In that perceptual part of my universe which I call your body, your mind and my mind meet and may be called conterminous. Your mind actuates that body and mine sees it; my thoughts pass into it as into their harmonious cognitive fulfilment; your emotions and volitions pass into it as causes into their effects.

But that percept hangs together with all our other physical percepts. They are of one stuff with it; and if it be our common possession, they must be so likewise. For instance, your hand lays hold of one end of a rope and my hand lays hold of the other end. We pull against each other. Can our two hands be mutual objects in this experience, and the rope not be mutual also? What is true of the rope is true of any other percept. Your objects are over and over again the same as mine. If I ask you where some object of yours is, our old Memorial Hall, for example, you point to my Memorial Hall with your hand which I see. If you alter an object in your world, put out a candle, for example, when I am present, my candle ipso facto goes out. It is only as altering my objects that I guess you to exist. If your objects do not coalesce with my objects, if they be not identically where mine are, they must be proved to be positively somewhere else. But no other location can be assigned for them, so their place must be what it seems to be, the same.

Practically, then, our minds meet in a world of objects which they share in common, which would still be there, if one or several of the minds were destroyed. I can see no formal objection to this supposition's being literally true. On the principles which I am defending, a 'mind' or 'personal consciousness' is the name for a series of experiences run together by certain definite transitions, and an objective reality is a series of similar experiences knit by different transitions. If one and the same experience can figure twice, once in a mental and once in a physical context (as I have tried, in my article on 'Consciousness,' to show that it can), one does not see why it might not figure thrice, or four times, or any number of times, by running into as many different mental contexts, just as the same point, lying at their intersection, can be continued into many different lines. Abolishing any number of contexts would not destroy the experience itself or its other contexts, any more than abolishing some of the point's linear continuations would destroy the others, or destroy the point itself.

I well know the subtle dialectic which insists that a term taken in another relation must needs be an intrinsically different term. The crux is always the old Greek one, that the same man can't be tall in relation to one neighbor, and short in relation to another, for that would make him tall and short at once. In this essay I can not stop to refute this dialectic, so I pass on, leaving my flank for the time exposed. But if my reader will only allow that the same 'now' both ends his past and begins his future; or that, when he buys an acre of land from his neighbor, it is the same acre that successively figures in the two estates; or that when I pay him a dollar, the same dollar goes into his pocket that came out of mine; he will also in consistency have to allow that the same object may conceivably play a part in, as being related to the rest of, any number of otherwise entirely different minds. This is enough for my present point: the common-sense notion of minds sharing the same object offers no special logical or epistemological difficulties of its own; it stands or falls with the general possibility of things being in conjunctive relation with other things at all.

In principle, then, let natural realism pass for possible. Your mind and mine may terminate in the same percept, not merely against it, as if it were a third external thing, but by inserting themselves into it and coalescing with it, for such is the sort of conjunctive union that appears to be experienced when a perceptual terminus 'fulfils.' Even so, two hawsers may embrace the same pile, and yet neither one of them touch any other part except that pile, of what the other hawser is attached to.

It is therefore not a formal question, but a question of empirical fact solely, whether, when you and I are said to know the 'same' Memorial Hall, our minds do terminate at or in a numerically identical percept. Obviously, as a plain matter of fact, they do not. Apart from color-blindness and such possibilities, we see the Hall in different perspectives. You may be on one side of it and I on another. The percept of each of us, as he sees the surface of the Hall, is moreover only his provisional terminus. The next thing beyond my percept is not your mind, but more percepts of my own into which my first percept develops, the interior of the Hall, for instance, or the inner structure of its bricks and mortar. If our minds were in a literal sense conterminous, neither could get beyond the percept which they had in common, it would be an ultimate barrier between them--unless indeed they flowed over it and became 'co-conscious' over a still larger part of their content, which (thought-transference apart) is not supposed to be the case. In point of fact the ultimate common barrier can always be pushed, by both minds, farther than any actual percept of either, until at last it resolves itself into the mere notion of imperceptibles like atoms or ether, so that, where we do terminate in percepts, our knowledge is only speciously completed, being, in theoretic strictness, only a virtual knowledge of those remoter objects which conception carries out.

Is natural realism, permissible in logic, refuted then by empirical fact? Do our minds have no object in common after all?

Yes, they certainly have Space in common. On pragmatic principles we are obliged to predicate sameness wherever we can predicate no assignable point of difference. If two named things have every quality and function indiscernible, and are at the same time in the same place, they must be written down as numerically one thing under two different names. But there is no test discoverable, so far as I know, by which it can be shown that the place occupied by your percept of Memorial Hall differs from the place occupied by mine. The percepts themselves may be shown to differ; but if each of us be asked to point out where his percept is, we point to an identical spot. All the relations, whether geometrical or causal, of the Hall originate or terminate in that spot wherein our hands meet, and where each of us begins to work if he wishes to make the Hall change before the other's eyes. Just so it is with our bodies. That body of yours which you actuate and feel from within must be in the same spot as the body of yours which I see or touch from without. 'There' for me means where I place my finger. If you do not feel my finger's contact to be 'there' in my sense, when I place it on your body, where then do you feel it? Your inner actuations of your body meet my finger there: it is there that you resist its push, or shrink back, or sweep the finger aside with your hand. Whatever farther knowledge either of us may acquire of the real constitution of the body which we thus feel, you from within and I from without, it is in that same place that the newly conceived or perceived constituents have to be located, and it is through that space that your and my mental intercourse with each other has always to be carried on, by the mediation of impressions which I convey thither, and of the reactions thence which those impressions may provoke from you.

In general terms, then, whatever differing contents our minds may eventually fill a place with, the place itself is a numerically identical content of the two minds, a piece of common property in which, through which, and over which they join. The receptacle of certain of our experiences being thus common, the experiences themselves might some day become common also. If that day ever did come, our thoughts would terminate in a complete empirical identity, there would be an end, so far as those experiences went, to our discussions about truth. No points of difference appearing, they would have to count as the same.