ny
reasoning, that agrees not with it. Thus should we mention the
word triangle, and form the idea of a particular equilateral one to
correspond to it, and should we afterwards assert, that the three
angles of a triangle are equal to each other, the other individuals of a
scalenum and isosceles, which we overlooked at first, immediately crowd
in upon us, and make us perceive the falshood of this proposition,
though it be true with relation to that idea, which we had formed. If
the mind suggests not always these ideas upon occasion, it proceeds
from some imperfection in its faculties; and such a one as is often the
source of false reasoning and sophistry. But this is principally the
case with those ideas which are abstruse and compounded. On other
occasions the custom is more entire, and it is seldom we run into such
errors.

Nay so entire is the custom, that the very same idea may be annext to
several different words, and may be employed in different reasonings,
without any danger of mistake. Thus the idea of an equilateral triangle
of an inch perpendicular may serve us in talking of a figure, of a
rectilinear figure, of a regular figure, of a triangle, and of an
equilateral triangle. AR these terms, therefore, are in this case
attended with the same idea; but as they are wont to be applied in a
greater or lesser compass, they excite their particular habits, and
thereby keep the mind in a readiness to observe, that no conclusion be
formed contrary to any ideas, which are usually comprized under them.

Before those habits have become entirely perfect, perhaps the mind may
not be content with forming the idea of only one individual, but may run
over several, in order to make itself comprehend its own meaning, and
the compass of that collection, which it intends to express by the
general term. That we may fix the meaning of the word, figure, we may
revolve in our mind the ideas of circles, squares, parallelograms,
triangles of different sizes and proportions, and may not rest on one
image or idea. However this may be, it is certain that we form the idea
of individuals, whenever we use any general term; that we seldom or
never can exhaust these individuals; and that those, which remain,
are only represented by means of that habit, by which we recall them,
whenever any present occasion requires it. This then is the nature of
our abstract ideas and general terms; and it is after this manner we
account for the foregoing para