These characteristics breathe throughout his poetry. The struggle for human weal; the resolution firm to martyrdom; the impetuous pursuit, the glad triumph in good; the determination not to despair; —such were the features that marked those of his works which he regarded with most complacency, as sustained by a lofty subject and useful aim.
In addition to these, his poems may be divided into two classes,—the purely imaginative, and those which sprang from the emotions of his heart. Among the former may be classed the “Witch of Atlas”, “Adonais”, and his latest composition, left imperfect, the “Triumph of Life”. In the first of these particularly he gave the reins to his fancy, and luxuriated in every idea as it rose; in all there is that sense of mystery which formed an essential portion of his perception of life—a clinging to the subtler inner spirit, rather than to the outward form—a curious and metaphysical anatomy of human passion and perception.
The second class is, of course, the more popular, as appealing at once to emotions common to us all; some of these rest on the passion of love; others on grief and despondency; others on the sentiments inspired by natural objects. Shelley’s conception of love was exalted, absorbing, allied to all that is purest and noblest in our nature, and warmed by earnest passion; such it appears when he gave it a voice in verse. Yet he was usually averse to expressing these feelings, except when highly idealized; and many of his more beautiful effusions he had cast aside unfinished, and they were never seen by me till after I had lost him. Others, as for instance “Rosalind and Helen” and “Lines written among the Euganean Hills”, I found among his papers by chance; and with some difficulty urged him to complete them. There are others, such as the “Ode to the Skylark and The Cloud”, which, in the opinion of many critics, bear a purer poetical stamp than any other of his productions. They were written as his mind prompted: listening to the carolling of the bird, aloft in the azure sky of Italy; or marking the cloud as it sped across the heavens, while he floated in his boat on the Thames.