To the errors of youth succeed the vices of mature age. Ambition and cupidity, envy and hatred concur to devour the very aliment of life. The storms which prostrate the moral faculties, equally sap the physical energy. Every debasing passion is a consuming poison. To what other source of evil can we assign those inquietudes and puerile anxieties, which disturb the days of the greater portion of mankind? They are occupied by trifling interests, and agitated by vain debates. They watch for futile excitements, and are in desolation from chimerical troubles. Pleasant emotions sustain life, and produce upon it the effect of a gentle current of air upon flame. Trains of thought habitually elevated, and sometimes inclined to revery, impart pure and true gayety to the soul. To be able to command this train is one of the rarest felicities of endowment. A distinguished physician recorded in his tablets the apparent paradox, that three quarters of men die of vexation or grief. Huffland has published a work, upon the art of prolonging life, full of interesting observations. ‘Philosophers,’ says he, ‘enjoy a delightful leisure. Their thoughts, generally estranged from vulgar interests, have nothing in common with those afflicting ideas, with which other men are continually agitated and corroded. Their reflections are agreeable by their variety, their vague liberty, and sometimes even by their frivolity. Devoted to the pursuits of their choice, the occupations of their taste, they dispose freely of their time. Oftentimes they surround themselves with young people, that their natural vivacity may be communicated to them, and, in some sort, produce a renewal of their youth.’ We may make a distinction between the different kinds of philosophy, in relation to their influence upon the duration of life. Those which direct the mind towards sublime contemplations, even were they in some degree superstitious, such as those of Pythagoras and Plato, are the most salutary. Next to them, I place those, the study of which, embracing nature, gives enlarged and elevated ideas upon infinity, the stars, the wonders of the universe, the heroic virtues, and other similar subjects. Such were those of Democritus, Philolaus, Xenophanes, the Stoics, and the ancient astronomers.’ ‘I may cite next those less profound thinkers, who instead of exacting difficult researches, seemed destined only to amuse the mind; the followers of which philosophy, deviating wide from vulgar opinion, peaceably sustain the arguments for and against the propositions advanced. Such was the philosophy of Carneades and the Academicians, to whom we may add the Grammarians and Rhetoricians.’