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