Sensual pleasure passes and vanishes, but the friendship between us, the mutual confidence, the delight of the heart, the enchantment of the soul, these things do not perish and can never be destroyed.
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.
Once your faith persuades you to believe what your intelligence declares absurd, beware, lest you likewise sacrifice your reason in the conduct of your life.