He sang a philosophy of love, and one effect of his philosophy was the suicide of Harriet Westbrook. He was, in this instance, ineffectual in not being able to translate his theory into experience in such a way that what was beautiful in theory would also be beautiful in experience. Where a theory was concerned, he did not recognise facts; he recognised only the theory. Thus, his theory that love is “the sole law which should govern the moral world” led him in _Laon and Cythna_ (later transformed into _The Revolt of Islam_) to make the lovers brother and sister. This circumstance was, he declared, “intended to startle the reader from the trance of ordinary life.” It was introduced “merely to accustom men to that charity and toleration which the exhibition of a practice widely differing from their own has a tendency to promote.” Who but an ineffectual angel would have thought of dragging idealised incest into a work of art solely with a view to the improvement of his readers’ morals? He did not wish his readers to practise incest: he merely wished to make them practise charity. Shelley, indeed, was a man always hastening towards an ideal world which at the touch of experience turned into a mirage. His political, like his ethical, theories had something mirage-like about them. He was a prophet who was so absorbed in the vision of the Promised Land that he had little thought to spare for the human nature that he was trying to incite to make the journey. His own imagination travelled fast as a ray of light, but he could not take human beings with him on so swift a journey. Hence, if he has been effectual, he has been so as an inspiration to the few. He has been ineffectual as regards achieving the earthly paradise he foretold in _The Mask of Anarchy_ and _Prometheus Unbound_. It ought, then, to be possible to appreciate Shelley without abusing Matthew Arnold. Every genius is limited, and we shall not admire the genius the less but the more if we recognise its limitations so clearly that we come to take them for granted. Thus, if we attempt to define Shelley’s genius as a poet, we have to start by recognising that there is a formless quality in most of his work when it is compared to the work of Keats or Wordsworth. His poems do not seem to be quite vertebrate--to have a beginning, a middle, and an end. Their path is as indeterminate as the path of the lark fluttering in the air. With Keats we stand still to survey the earth. With Wordsworth we walk. But Shelley, like his skylark, is a “scorner of the ground,” and our feet do not always touch the earth when we are in his company. Even when he journeys by land or water, he rushes us along as though the air were the only element, and we are dizzied by the speed with which we are carried from landscape to landscape. In _Alastor_, scene succeeds scene faster than the eye can seize it.