[Excerpts from The Principles of Psychology, 1890 by William James; Volume One, Chapter IX: “The Stream of Thought”]
Every thought tends to be part of a personal consciousness.
My thought belongs with my other thoughts, and your thoughts with your other thoughts. Whether anywhere in the room there be a mere thought, which is nobody’s thought, we have no means of ascertaining, for we have no experience of its like. Each of these minds keeps its own thoughts to itself. There is no giving or bartering between them. No thought even comes into direct sight of a thought in another personal consciousness than its own. Absolute insulation, irreducible pluralism is the law. It seems as if the elementary psychic fact were not thought or this thought or that thought, but my thought, every thought being owned… On these terms the personal self rather than the thought might be regarded as the immediate datum of psychology. The universal conscious fact is not ‘feelings and thoughts exist’ but ‘I think’ and ‘I feel.’
What now is the common whole. The natural name for it is myself, I, or me…
When Paul and Peter wake up in the same bed, and recognize that they have been asleep, each one of them mentally reaches back and makes connection with but one of the two streams of thought that were broken by the sleeping hours… Peter’s present instantly finds out Peter’s past, and never by mistake knits itself on to that of Paul. Paul’s thought in turn is as little liable to go astray. The past thought of Peter is appropriated by the present Peter alone… The community of self is what the time-gap cannot break in twain…
The mind, in short, works on the data it receives very much as a sculptor works on his block of stone. In a sense the statue stood there from eternity. But there are a thousand different ones beside it, and the sculptor alone is to thank for having extricated this one from the rest. Just so the world of each of us, howsoever different our several views of it may be, all lay embedded in the primordial chaos of sensations, which gave the mere matter to the thought of all of us indifferently. We may, if we like, by our reasonings unwind things back to that black and jointless continuity of space and moving clouds of swarming atoms which science calls the only real world. But all the while the world we feel and live in will be that which our ancestors and we, by slowly cumulative strokes of choice, have extricated out of this, like sculptors, by simply rejecting certain portions of the given stuff. Other sculptors, other statues from the same stone! Other minds, other worlds from the same monotonous and inexpressive chaos! My world is but one in a million alike embedded, alike real to those who may extract them. How different must be the worlds in the consciousnesses of ant, cuttle-fish, or crab!
But in my mind and your mind the rejected portions and the selected portions of the original world-stuff are to a great extent the same. The human race as a whole largely agrees as to what it shall notice and name, and what not. And among the noticed parts we select in much the same way for accentuation and preference or subordination and dislike. There is, however, one entirely extraordinary case in which no two men ever are known to choose alike. One great splitting of the whole universe into two halves is made by each of us; and for each of us almost all of the interest attaches to one of the halves; but we all draw the line of division between them in a different place. When I say that we all call the two halves by the same names, and that those names are ‘me‘ and ‘not-me‘ respectively, it will at once be seen what I mean. The altogether unique kind of interest which each human mind feels in those parts of creation, which it can call me or mine may be a moral riddle, but it is a fundamental psychological fact. No mind can take the same interest in his neighbor’s me as in his own. The neighbor’s me falls together with all the rest of things in one foreign mass, against which his own me stands out in startling relief. Even the trodden worm, as Lotze somewhere says, contrasts his own suffering self with the whole remaining universe, though he have no clear conception either of himself or of what the universe may be. He is for me a mere part of the world; for him it is I who am the mere part. Each of us dichotomizes the Kosmos in a different place.