The thoroughness and devotion of a student tell their own tale in such expressions as the 'studio disposta fideli,' and the 'noctes vigilare serenas' in the dedication to Memmius, and in the more enthusiastic acknowledgment of the source from which he drew his philosophy at iii. 29, etc.-- Tuisque ex, inclute, chartis, Floriferis ut apes in saltibus omnia libant, Omnia nos itidem depascimur aurea dicta. The absorbing interest with which he carried on the work of enquiry and of composition appears in illustrations of his argument drawn from his own pursuits; as where (ii. 979) in arguing that, if the atoms have the properties of sense, those of which man is compounded must have the intellectual attributes of man, he says,-- Multaque de rerum mixtura dicere callent Et sibi proporro quae sint primordia quaerunt;[362] and, again (at iv. 969), in explaining how men in their dreams seem to carry on the pursuits to which they are most devoted, how lawyers seem to plead their causes, generals to fight their battles over again, sailors to battle with the elements, he adds these lines:-- Nos agere hoc autem et naturam quaerere rerum Semper et inventam patriis exponere chartis.[363] His frequent use of the sacrificial phrase 'Hoc age,' affords evidence of the religious earnestness with which he had devoted himself to his task. The feeling animating him through all his great adventure,--through the wastest flats as well as the most commanding heights over which it leads him,--is something different from the delight of a poet in his art, of a scholar in his books, of a philosopher in his thought, of a naturalist in his observation. All of these modes of feeling are combined with the passion of his whole moral and intellectual being, aroused by the contemplation of the greatest of all themes--'maiestas cognita rerum'--and concentrated on the greatest of practical ends, the emancipation and elevation of human life. The life of contemplation which he alone among the Romans deliberately chose and realised he carried out with Roman energy and fortitude. It was with him no life of indolent musing, but one of thought and study, varied and braced by original observation. It was a life, also, of strenuous literary effort employed in giving clearness to obscure materials, and in eliciting poetical charm from a language to which the musical cadences of verse had been hitherto almost unknown. Above all, it was the life of one who, while feeling the spell of Nature more profoundly than any poet who had gone before him, did not in that new rapture forget 'The human heart by which we live.'