If it be true, that the _understanding_ and the _will_ are the _two eminent faculties of the reasonable soul_, it follows necessarily, that _wisdom_ and _virtue_, (which are the best improvements of these two faculties,) must be the perfection also of our _reasonable being_; and consequently, _the undeniable foundation of a happy life_. There is not any duty to which Providence has not annexed a blessing; nor any institution of Heaven which, even in this life, we may not be the better for; not any temptation, either of fortune or of appetite, that is not subject to our reason; nor any passion or affliction for which virtue has not provided a remedy. So that it is our own fault if we either fear or hope for anything; which two affections are the root of all our miseries. From this general prospect of the _foundation_ of our _tranquillity_, we shall pass by degrees to a particular consideration of the _means_ by which it may be _procured_, and of the _impediments_ that _obstruct_ it; beginning with that _philosophy_ which principally regards our manners, and instructs us in the measures of a virtuous and quiet life.