The system of Descartes... seemed to give a plausible reason for all those phenomena; and this reason seemed more just, as it is simple and intelligible to all capacities. But in philosophy, a student ought to doubt of the things he fancies he understands too easily, as much as of those he does not understand.
What is called happiness is an abstract idea, composed of various ideas of pleasure; for he who has but a moment of pleasure is not a happy man, in like manner that a moment of grief constitutes not a miserable one.