It is the business of the philosopher to analyze the objects of nature. He must pay least attention to those which chiefly affect the sense and imagination, while he minutely considers others, which, though less striking, are more useful for classification, and the chief purposes he has in view. The poet, on the other hand, avoiding dry and abstract definitions, rather combines than analyzes, and dwells more on the sensible phænomena of nature, than her mysterious and scientific workings. Thus, what the botanist considers is the number of _stamina_, and their situation in a flower, while the Muse describes only its colours, and the influence of its odours— “She loves the rose, by rivers loves to dream, Nor heeds why blooms the rose, why flows the stream— She loves its colours, though she may not know, Why sun-born Iris paints the showery bow.” But though philosophic poetry be, of all others, the most unfavourable for the exertion of poetical genius, its degree of beauty and interest will, in a great measure, depend on what parts of his subject the poet selects, and on the extent and number of digressions of which it admits. It is evident, that the philosophic poet should pass over as lightly as may be, all dry and recondite doctrines, and enlarge on the topics most susceptible of poetical ornament. “Le Tableau de la Nature Physique,” says Voltaire, “est lui seule d’une richesse, d’une varieté, d’une etendue à occuper des siécles d’étude; mais tous les details ne sont pas favorable à la poésie. On n’ exige pas du poete les meditations du physicien et les calculs de l’astronomie: c’est à l’observateur à déterminer l’attraction et les mouvemens des corps celestes; c’est au poete à peindre leur balancement, leur harmonie, et leurs immuables révolutions. L’un distinguera les classes nombreuses d’etres organisés qui peuplent les elémens divers; l’autre décririra d’un trait hardi, lumineux et rapide cette echelle immense et continue, ou les limites des regnes se confondent. Que le confident de la nature develope le prodige de la greffe des arbres—c’est assez pour Virgile de l’exprimer en deux beaux vers— “Exiit ad cœlum ramis felicibus arbos, Miraturque novas frondes et non sua poma(435).”