BOOK II PART III
which of all other exercises of the mind is the
most pleasant and agreeable.
But though the exercise of genius be the prin-
cipal source of that satisfaction we receive from
the sciences, yet I doubt, if it be alone suffi-
cient to give us any considerable enjoyment.
The truth we discover must also be of some
importance. It is easy to multiply algebraical
problems to infinity, nor is there any end in the
discovery of the proportions of conic sections;
though few mathematicians take any pleasure
in these researches, but turn their thoughts
to what is more useful and important. Now
the question is, after what manner this utility
and importance operate upon us? The diffi-
culty on this head arises from hence, that many
philosophers have consumed their time, have
destroyed their health, and neglected their for-