5. From a wrong connexion of ideas.
Some of our ideas have a natural correspondence and connexion one with
another: it is the office and excellency of our reason to trace these, and hold them together in that union and
correspondence which is founded in their peculiar beings. Besides this, there is another connexion of ideas wholly
owing to chance or custom. Ideas that in themselves are not all of kin, come to be so united in some men's minds,
that it is very hard to separate them; they always keep in company, and the one no sooner at any time comes into
the understanding, but its associate appears with it; and if they are more than two which are thus united, the whole
gang, always inseparable, show themselves together.