BOOK I PART II
common, but in many cases certain and infal-
lible. When the measure of a yard and that of a
foot are presented, the mind can no more ques-
tion, that the first is longer than the second,
than it can doubt of those principles, which are
the most clear and self-evident.
There are therefore three proportions, which
the mind distinguishes in the general appear-
ance of its objects, and calls by the names of
greater, less and equal. But though its deci-
sions concerning these proportions be some-
times infallible, they are not always so; nor are
our judgments of this kind more exempt from
doubt and error than those on any other sub-
ject. We frequently correct our first opinion by
a review and reflection; and pronounce those
objects to be equal, which at first we esteemed
unequal; and regard an object as less, though