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 ...

124 ABSTRACTION,
of propositions involving general terms. But the observations
he has made, (admitting them in their full extent,) do not in the
least affect the question about the necessity of signs, to enable
us to speculate about such propositions. The vague use which
metaphysical writers have made of the word conception, (of
which I had occasion to take notice in a former chapter,) has
contributed in part to embarrass this subject. That we cannot
conceive universals in a way at all analogous to that in which
we conceive an absent object of sense, is granted on both sides.
Why then should we employ the same word, conception, to ex
press two operations of the mind which are essentially different?
When we speak of conceiving or understanding a general proposition, we mean nothing more than that we have a conviction,
(founded on our previous use of the words in which it is expressed,) that we have it in our power, at pleasure, to substitute,
instead of the general terms, some one of the individuals comprehended under them. When we hear a proposition announced,
of which the terms are not familiar to us, we naturally desire to
have it exemplified, or illustrated, by means of some particular
instance; and when we are once satisfied by such an application, that we have the interpretation of the proposition at all
times in our power, we make no scruple to say, that we conceive or understand its meaning, although we should not extend
our views beyond the words in which it is announced, or even
although no particular exemplification of it should occur to us at
the moment. It is in this sense only, that the terms of any general proposition can possibly be understood; and therefore Dr.
Reid's argument does not, in the least, invalidate the doctrine
of the Nominalists, that, without the use of language, (muder
which term I comprehend every species of signs,) we should
never have been able to extend our speculations beyond individuals.
That in many cases, we may safely employ in our reasonings
general terms, the meaning of which we are not eve:X able to
interpret in this way, and consequently, which are to As wholly
insignificant, I had occasion already to demonstrate, ii. a former
part of this section.