Again, in the splendid praise of Epicurus, which opens the fifth book, he says that we may live without grain or wine, But well one can not live without pure heart.[25] The only Greek philosophers, besides Epicurus, of whom Lucretius speaks in terms of praise are Democritus, from whom Epicurus borrowed the atomic theory, and Empedocles. Perhaps Lucretius imitates in his work the poem of Empedocles, which bore the same title. At any rate, Empedocles was a man of exalted modes of thought and dignified, poetic expression, qualities which would naturally awaken admiration in the mind of Lucretius. [Sidenote: His reading, observation, and love of nature.] That Lucretius was well acquainted with the great works of Greek literature and with the writings of Nævius, Ennius, Pacuvius, Lucilius, and Accius, is evident from direct references to them, or imitations of them. But he was not merely a student of books. His power of observation and his love of nature are shown in many passages, as where he describes the raging winds and rivers,[26] the life and motion of an army,[27] the striking features of the island of Sicily,[28] the echo in the mountains,[29] or pleasant repose under a shady tree on the grass by the river side.[30] [Sidenote: Two famous passages.] The poem opens with an invocation to Venus, which is justly famous. The first lines are: Goddess from whom descends the race of Rome, Venus, of earth and heaven supreme delight, Hail, thou that all beneath the starry dome— Lands rich with grain and seas with navies white— Blessest and cherishest! Where thou dost come Enamelled earth decks her with posies bright To meet thy advent; clouds and tempests flee, And joyous light smiles over land and sea.[31] Another famous passage is the beginning of Book ii, which has been translated into English hexameters as follows: Sweet, when the great sea’s water is stirred to its depth by the storm winds, Standing ashore to descry one afar off mightily struggling; Not that a neighbor’s sorrow to you yields dulcet enjoyment; But that the sight hath a sweetness, of ills ourselves are exempt from. Sweet ’tis too to behold, on a broad plain mustering war-hosts Arm them for some great battle, one’s self unscathed by the danger; Yet still happier this: To possess, impregnably guarded, Those calm heights of the sages which have for an origin Wisdom; Thence to survey our fellows, observe them this way and that way Wander amid Life’s paths, poor stragglers seeking a highway; Watch mind battle with mind, and escutcheon rival escutcheon; Gaze on that untold strife, which is waged ’neath the sun and the starlight, Up as they toil on the surface whereon rest Riches and Empire.[32]