If, again, he has ever seen a house, he will know what
_house_ denotes; not otherwise. Or suppose, that, not knowing, he ask
what a house is, and that the first speaker attempt to explain by
telling him that it is such and such a structure, built of brick, wood,
or stone; then it is assumed that he has seen stone, wood, or brick,
that he has seen the act of building, or at least its result;--and in
fine, the explanation, every syllable of it, can do no more than appeal
to perceptions of which the questioner is assumed to have had
experience.

We do, indeed, gain an approximate knowledge of things we have never
seen. For example, I have an imperfect notion of a banian-tree, though I
have never seen one; but it is only by having seen other trees, and by
having also had the perceptions to which appeal is made in describing
the peculiarities of the banian. So he who is born blind may learn so
much concerning outward objects as the senses of touch, hearing, smell,
and taste can impart to him; and he may profit by verbal information to
such extent as these perceptions enable him. But the perception itself,
and so thought, faith, and in fine all mental experience whatsoever,
whether of high order or low, whether relating to objects within us or
to objects without, take place only in the privacy of our own minds, and
are in their substance not to be transferred.

Observe with precision what is here said. The mental experience of each
man, if it be of any spiritual depth, has transacted itself in his
nature in virtue, to a most important degree, of spiritual relationship
with other human beings. There never was an act of development in any
man's soul that did not imply a humanity, and involve the virtue of
social affinity. I should be dumb, but for the ears of others; I should
be deaf, that is, my human ear would be closed, but for human voices;
and there is no particle of human energy, and no tint of human coloring,
for which we are not, in part, indebted to vital human fellowship.
Nevertheless, of this experience, though in the absence of social
connection it could not have occurred, not one jot nor tittle can be
made over to another by means of words. It can hoist its verbal signal,
and the like experience in other souls may interpret the sign; it can do
no more.

Men may, indeed, _commune_; that is, they may by verbal conference enter
mutually into a sense of an already existing unity of inward experience;
and there are