er causes outward as well as inward; and although it
must be obvious to reflection, that all its ideas, perceptions, and
emotions, are, with respect to itself, of a spiritual nature--bearing such
a relation to the spiritual substance in which alone they appear, as bodily
motion is seen to bear to material substances; yet we know, from experience
and observation, that they who are acquainted with words, are apt to think
in words--that is, mentally to associate their internal conceptions with
the verbal signs which they have learned to use. And though I do not
conceive the position to be generally true, that words are to the mind
itself the necessary instruments of thought, yet, in my apprehension, it
cannot well be denied, that in some of its operations and intellectual
reaches, the mind is greatly assisted by its own contrivances with respect
to language. I refer not now to the communication of knowledge; for, of
this, language is admitted to be properly the instrument. But there seem to
be some processes of thought, or calculation, in which the mind, by a
wonderful artifice in the combination of terms, contrives to prevent
embarrassment, and help itself forward in its conceptions, when the objects
before it are in themselves perhaps infinite in number or variety.

19. We have an instance of this in numeration. No idea is more obvious or
simple than that of unity, or one. By the continual addition of this, first
to itself to make two, and then to each higher combination successively, we
form a series of different numbers, which may go on to infinity. In the
consideration of these, the mind would not be able to go tar without the
help of words, and those peculiarly fitted to the purpose. The
understanding would lose itself in the multiplicity, were it not aided by
that curious concatenation of names, which has been contrived for the
several parts of the succession. As far as _twelve_ we make use of simple
unrelated terms. Thenceforward we apply derivatives and compounds, formed
from these in their regular order, till we arrive at a _hundred_. This one
new word, _hundred_, introduced to prevent confusion, has nine hundred and
ninety-nine distinct repetitions in connexion with the preceding terms, and
thus brings us to a _thousand_. Here the computation begins anew, runs
through all the former combinations, and then extends forward, till the
word _thousand_ has been used nine hundred and ninety-nine thousand times;
and then,