Elements of the philosophy of the human mind. By Dugald Stewart. Rev. and abridged, with critical and explanatory notes, for the use of colleges and schools. By Francis Bowen ...

ABST'ILtACION. 111
meaning of our expressions is once fixed by definitions,) it may
be carried on entirely by the use of signs, without attending,
during the time of the process, to the things signified.
The conclusion to which the foregoing observations lead, appears to me to be decisive of the question, with respect to the objects of our thoughts when we employ general terms; for if it be
granted, that words, even when employed without any reference
to their particular signification, form an instrument of thought
sufficient for all the purposes of reasoning; the only shadow
of an argument in proof of the common doctrine on the subject,
(I mean that which is founded on the impossibility of explaining this process of the mind on any other hypothesis,) falls to
the ground. Nothing less, surely, than a conviction of this impossibility, could have so long reconciled philosophers to an
hypothesis unsupported by any direct evidence; and acknowledged, even by its warmest defenders, to involve much difficulty
and mystery.
Uses of illustrated and abstract reasoning. - It does not fall
within my plan to enter, in this part of my work, into a par.
ticular consideration of the practical consequences which follow
from the foregoing doctrine. I cannot, however, help remarking the importance of cultivating, on the one hand, a talent for
ready and various illustration; and, on the other, a habit of reasoning by means of general terms. The former talent is necessary, not only for correcting and limiting our general conclusions, but for enabling us to apply our knowledge, when occasion
requires, to its real practical use. The latter serves the double
purpose, of preventing our attention from being distracted during the course of our reasonings, by ideas which are foreign to
the point in question, and of diverting the attention from those
conceptions of particular objects and particular events which
might disturb the judgment, by the ideas and feelings which are
apt to be associated with them, in consequence of our own casual experience.
This last observation points out to us, also, one principal
foundation of the art of the orator. As his object is not so much
to inform and satisfy the understandings of his hearers, as to