But a simpler and perhaps more decisive proof of the near and hospitable relations of poetry and science is presented in the cases of their actual union in the same person. When imagination ceases to be mistress and becomes servant to observation, your poet turns scientist. When observation yields the scepter to imagination, your scientist turns poet. The names of Maxwell, Tyndall, Romanes and Huxley suggest themselves as examples of scientists of the first rank whose poetic gift is manifest in their published poems. Of the poets of the first rank who have shown the scientific turn and interest, one thinks first of Tennyson. He studied medicine until he imagined that he had all the diseases set out in the books. His interest in astronomy he maintained to the time of the 'twilight and evening star.' From his student days at Cambridge when 'the fairy tales of science' first won him, even down to the 'Locksley Hall Sixty Years After,' he meditated deeply on evolution. The scientists of his period looked upon him as their most intelligent mouthpiece in the world of letters. Goethe, it is well known, felt more satisfaction in his scientific achievements than in the poems which made him the chief figure in German literature. It was a comparatively small thing to have written 'Faust,' but to be the only person of his century who understood the science of colors—that was a thing to be proud of.
Classic, as well as modern, literature offers illustrations of the union of the poetic and the scientific interest. There are some extant lines of Virgil headed, 'Virgil abandons other studies and embraces the Epicurean Philosophy.' That this love of science—for ancient philosophy included science—was no transient passion is attested by poems on natural objects and by passages in the Georgics, the Eclogues and the Æneid. His last fatal journey to Greece and Asia was undertaken in order that he might complete the Æneid, and then devote the remainder of his life to science. But in all the history of literature, the best example of the fellowship of science and poetry is Lucretius, the poet in whom we are here particularly interested; for he was not at one time poet and at another time scientist, but rather both at once. It is Mrs. Browning's judgment that Lucretius 'died chief poet on the Tiber-side,' and a Quarterly Reviewer has recently declared him to be Rome's truest man of science. But such eminence in the two spheres is paralleled in the case of Goethe. What makes the work of Lucretius quite unique is the fact that his first-rate poetic capacity cooperates with his capacity for science in the same task. The poet's imagination kindles into beauty the scientist's perceptions, and the issue is a poetical treatise on physics and biology, or, if you prefer, a science poem.
It is true that a certain type of mind in the eighteenth century was drawn to Lucretius, recognizing in him a sort of fellowship oi