Now what justifies my critic in being as lenient as this? This singularly inadequate consciousness of mine, made up of symbols that neither resemble nor affect the realities they stand for,—how can he be sure it is cognizant of the very realities he has himself in mind?
He is sure because in countless like cases he has seen such inadequate and symbolic thoughts, by developing themselves, terminate in percepts that practically modified and presumably resembled his own. By 'developing' themselves is meant obeying their tendencies, following up the suggestions nascently present in them, working in the direction in which they seem to point, clearing up the penumbra, making distinct the halo, unravelling the fringe, which is part of their composition, and in the midst of which their more substantive kernel of subjective content seems consciously to lie. Thus I may develop my thought in the Paley direction by procuring the brown leather volume and bringing the passages about the animal kingdom before the critic's eyes. I may satisfy him that the words mean for me just what they mean for him, by showing him IN CONCRETO the very animals and their arrangements, of which the pages treat. I may get Newton's works and portraits; or if I follow the line of suggestion of the wig, I may smother my critic in seventeenth-century matters pertaining to Newton's environment, to show that the word 'Newton' has the same LOCUS and relations in both our minds. Finally I may, by act and word, persuade him that what I mean by God and the heavens and the analogy of the handiworks, is just what he means also.
My demonstration in the last resort is to his SENSES. My thought makes me act on his senses much as he might himself act on them, were he pursuing the consequences of a perception of his own. Practically then MY thought terminates in HIS realities. He willingly supposes it, therefore, to be OF them, and inwardly to RESEMBLE what his own thought would be, were it of the same symbolic sort as mine. And the pivot and fulcrum and support of his mental persuasion, is the sensible operation which my thought leads me, or may lead, to effect—the bringing of Paley's book, of Newton's portrait, etc., before his very eyes.
In the last analysis, then, we believe that we all know and think about and talk about the same world, because WE BELIEVE OUR PERCEPTS ARE POSSESSED BY US IN COMMON. And we believe this because the percepts of each one of us seem to be changed in consequence of changes in the percepts of someone else. What I am for you is in the first instance a percept of your own. Unexpectedly, however, I open and show you a book, uttering certain sounds the while. These acts are also your percepts, but they so resemble acts of yours with feelings prompting them, that you cannot doubt I have the feelings too, or that the book is one book felt in both our worlds. That it is felt in the same way, that my feelings of it resemble yours, is something of which we never can be sure, but which we assume as the simplest hypothesis that meets the case. As a matter of fact, we never ARE sure of it, and, as ERKENNTNISSTHEORETIKER, we can only say that of feelings that should NOT resemble each other, both could not know the same thing at the same time in the same way. [Footnote: Though both might terminate in the same thing and be incomplete thoughts 'about' it.] If each holds to its own percept as the reality, it is bound to say of the other percept, that, though it may INTEND that reality, and prove this by working change upon it, yet, if it do not resemble it, it is all false and wrong. [Footnote: The difference between Idealism and Realism is immaterial here. What is said in the text is consistent with either theory. A law by which my percept shall change yours directly is no more mysterious than a law by which it shall first change a physical reality, and then the reality change yours. In either case you and I seem knit into a continuous world, and not to form a pair of solipsisms.]
If this be so of percepts, how much more so of higher modes of thought! Even in the sphere of sensation individuals are probably different enough. Comparative study of the simplest conceptual elements seems to show a wider divergence still. And when it comes to general theories and emotional attitudes towards life, it is indeed time to say with Thackeray, 'My friend, two different universes walk about under your hat and under mine.'
What can save us at all and prevent us from flying asunder into a chaos of mutually repellent solipsisms? Through what can our several minds commune? Through nothing but the mutual resemblance of those of our perceptual feelings which have this power of modifying one another, WHICH ARE MERE DUMB KNOWLEDGES-OF-ACQUAINTANCE, and which must also resemble their realities or not know them aright at all. In such pieces of knowledge-of-acquaintance all our knowledge-about must end, and carry a sense of this possible termination as part of its content. These percepts, these termini, these sensible things, these mere matters-of-acquaintance, are the only realities we ever directly know, and the whole history of our thought is the history of our substitution of one of them for another, and the reduction of the substitute to the status of a conceptual sign. Contemned though they be by some thinkers, these sensations are the mother-earth, the anchorage, the stable rock, the first and last limits, the terminus a quo and the terminus ad quem of the mind. To find such sensational termini should be our aim with all our higher thought. They end discussion; they destroy the false conceit of knowledge; and without them we are all at sea with each other's meaning. If two men act alike on a percept, they believe themselves to feel alike about it; if not, they may suspect they know it in differing ways. We can never be sure we understand each other till we are able to bring the matter to this test. [Footnote: 'There is no distinction of meaning so fine as to consist in anything but a possible difference of practice.... It appears, then, that the rule for attaining the [highest] grade of clearness of apprehension is as follows: Consider what effects, which might conceivably have practical bearings, we conceive the object of our conception to have. Then, our conception of these effects is the whole of our conception of the object.' Charles S. Peirce: 'How to make our Ideas clear,' in Popular Science Monthly, New York, January, 1878, p. 293.] This is why metaphysical discussions are so much like fighting with the air; they have no practical issue of a sensational kind. 'Scientific' theories, on the other hand, always terminate in definite percepts. You can deduce a possible sensation from your theory and, taking me into your laboratory, prove that your theory is true of my world by giving me the sensation then and there. Beautiful is the flight of conceptual reason through the upper air of truth. No wonder philosophers are dazzled by it still, and no wonder they look with some disdain at the low earth of feeling from which the goddess launched herself aloft. But woe to her if she return not home to its acquaintance; Nirgends haften dann die unsicheren Sohlen—every crazy wind will take her, and, like a fire-balloon at night, she will go out among the stars.
NOTE.—The reader will easily see how much of the account of the truth-function developed later in Pragmatism was already explicit in this earlier article, and how much came to be defined later. In this earlier article we find distinctly asserted:—
1. The reality, external to the true idea;
2. The critic, reader, or epistemologist, with his own belief, as warrant for this reality's existence;
3. The experienceable environment, as the vehicle or medium connecting knower with known, and yielding the cognitive RELATION;
4. The notion of POINTING, through this medium, to the reality, as one condition of our being said to know it;
5. That of RESEMBLING it, and eventually AFFECTING it, as determining the pointing to IT and not to something else.
6. The elimination of the 'epistemological gulf,' so that