The more exquisite any good is, of which a small specimen is afforded us, the sharper is the evil, allied to it; and few exceptions are found to this uniform law of nature. The most sprightly wit borders on madness; the highest effusions of joy produce the deepest melancholy; the most ravishing pleasures are attended with the most cruel lassitude and disgust; the most flattering hopes make way for the severest disappointments. And, in general, no course of life has such safety (for happiness is not to be dreamed of) as the temperate and moderate, which maintains, as far as possible, a mediocrity, and a kind of insensibility, in every thing. As the good, the great, the sublime, the ravishing are found eminently in the genuine principles of theism; it may be expected, from the analogy of nature, that the base, the absurd, the mean, the terrifying will be equally discovered in religious fictions and chimeras.
Nature has pointed out a mixed kind of life as most suitable to the human race, and secretly admonished them to allow none of these biases to draw too much, so as to incapacitate them for other occupations and entertainments. Indulge your passion for science, says she, but let your science be human, and such as may have a direct reference to action and society. Abstruse thought and profound researches I prohibit, and will severely punish, by the pensive melancholy which they introduce, by the endless uncertainty in which they involve you, and by the cold reception which your pretended discoveries shall meet with, when communicated. Be a philosopher; but, amidst all your philosophy, be still a man.