BOOK I PART I
These are therefore the principles of union or
cohesion among our simple ideas, and in the
imagination supply the place of that insepara-
ble connexion, by which they are united in our
memory. Here is a kind ofattraction, which
in the mental world will be found to have as
extraordinary effects as in the natural, and to
shew itself in as many and as various forms. Its
effects are every where conspicuous; but as to
its causes, they are mostly unknown, and must
be resolved into original qualities of human na-
ture, which I pretend not to explain. Nothing
is more requisite for a true philosopher, than
to restrain the intemperate desire of searching
into causes, and having established any doc-
trine upon a sufficient number of experiments,
rest contented with that, when he sees a farther
examination would lead him into obscure and
uncertain speculations. In that case his enquiry