BOOK I PART II
Of the three relations above-mentioned that
of resemblance is the most fertile source of er-
ror; and indeed there are few mistakes in rea-
soning, which do not borrow largely from that
origin. Resembling ideas are not only related
together, but the actions of the mind, which
we employ in considering them, are so little
different, that we are not able to distinguish
them. This last circumstance is of great conse-
quence, and we may in general observe, that
wherever the actions of the mind in forming
any two ideas are the same or resembling, we
are very apt to confound these ideas, and take
the one for the other. Of this we shall see
many instances in the progress of this treatise.
But though resemblance be the relation, which
most readily produces a mistake in ideas, yet
the others of causation and contiguity may also
concur in the same influence. We might pro-