e or word that we use. It is
absolutely useless to talk to him, because nothing that we say conveys
any meaning to his mind. We can supply him no dictionary, because by
hypothesis he knows no language to which we have access. How shall we
proceed to communicate our ideas to him? Clearly there is but one
possible way--namely, through his senses. Outside of this means of
bringing him in contact with us we can have no communication with him.
We, therefore, begin by showing him sensible objects, and letting him
understand that certain words which we use correspond to those objects.
After he has thus acquired a small vocabulary, we make him understand
that other terms refer to relations between objects which he can
perceive by his senses. Next he learns, by induction, that there are
terms which apply not to special objects, but to whole classes of
objects. Continuing the same process, he learns that there are certain
attributes of objects made known by the manner in which they affect his
senses, to which abstract terms are applied. Having learned all this,
we can teach him new words by combining words without exhibiting
objects already known. Using these words we can proceed yet further,
building up, as it were, a complete language. But there is one limit at
every step. Every term which we make known to him must depend
ultimately upon terms the meaning of which he has learned from their
connection with special objects of sense.

To communicate to him a knowledge of words expressive of mental states
it is necessary to assume that his own mind is subject to these states
as well as our own, and that we can in some way indicate them by our
acts. That the former hypothesis is sufficiently well established can
be made evident so long as a consistency of different words and ideas
is maintained. If no such consistency of meaning on his part were
evident, it might indicate that the operations of his mind were so
different from ours that no such communication of ideas was possible.
Uncertainty in this respect must arise as soon as we go beyond those
mental states which communicate themselves to the senses of others.

We now see that in order to communicate to our foreigner a knowledge of
language, we must follow rules similar to those necessary for the
stability of a building. The foundation of the building must be well
laid upon objects knowable by his five senses. Of course the mind, as
well as the external object, may be a factor