These evidences of the exceedingly imperfect knowledge of his time are fully illustrated in Seneca’s chapters. He quotes some two dozen of previous writers who had dealt with the same or cognate subjects. It is needless to say that they were Greeks, no place having yet been found in Latin literature for treatises on Science. The author most frequently cited by him is Aristotle, whose _Meteorologica_ he had evidently studied with care. He gives frequent quotations from that work, but even where he does not specifically quote, his views generally accord with those of the great philosopher and naturalist.[102] Almost the only quotations from the works of his own countrymen are verses from some of the poets, especially from Virgil and Ovid. It is remarkable that he makes only one quotation from Lucretius, although he would have found in that poet’s noble work many passages more apposite to his subject than those which he has taken from the _Aeneid_, the _Georgics_, and the _Metamorphoses_. We may suppose that these works were favourites with him, and that he knew much of them by heart, but that he was less familiar with the _De Rerum Natura_. [102] Seneca’s indebtedness to Aristotle is emphatically expressed by Barthélemy Saint-Hilaire in the Dissertation prefixed to his translation of the _Meteorologica_ (_Météorologie d’Aristote_, 1863, pp. lxix-lxx). It is manifest from the present volume that its author, like Lucretius before him, had a lofty conception of the dignity and moral influence of the study of nature. This pursuit seemed to him to raise us above the sordid things of life and to withdraw the mind from the body--a dissociation so eminently beneficial to our higher aspirations. He believed that in the study of the hidden phenomena of the universe a mental alacrity is developed which will be found to be not without practical utility in the conduct of affairs that lie nearer the surface (113). With this clear recognition of the importance of his theme he resolved in his old age to enter upon a task which other less worthy pursuits had hindered him from pursuing. He would now attempt to survey the universe, unravel its secrets, and give the results of his studies to the world (109). It was not, however, his aim to compose a systematic treatise on Natural Philosophy, but rather to take up some special subjects and deal with them in the light of what had already been written upon them, and of what his own reflections suggested. His undertaking assumed the form of a series of epistolary essays addressed to his friend Lucilius Junior, procurator of Sicily. The literary shape thus selected allowed the use of an unconstrained, almost colloquial, style which would not have been suitable to a more ambitious work.