When I was a boy in Dublin I was one of a group who rented a room in a mean street to discuss philosophy. My fellow-students got more and more interested in certain modern schools of mystical belief, and I never found anybody to share my one unshakable belief. I thought that whatever of philosophy has been made poetry is alone permanent, and that one should begin to arrange it in some regular order, rejecting nothing as the make-believe of the poets. I thought, so far as I can recollect my thoughts after so many years, that if a powerful and benevolent spirit has shaped the destiny of this world, we can better discover that destiny from the words that have gathered up the heart's desire of the world, than from historical records, or from speculation, wherein the heart withers. Since then I have observed dreams and visions very carefully, and am now certain that the imagination has some way of lighting on the truth that the reason has not, and that its commandments, delivered when the body is still and the reason silent, are the most binding we can ever know. I have re-read _Prometheus Unbound_, which I had hoped my fellow-students would have studied as a sacred book, and it seems to me to have an even more certain place than I had thought, among the sacred books of the world. I remember going to a learned scholar to ask about its deep meanings, which I felt more than understood, and his telling me that it was Godwin's _Political Justice_ put into rhyme, and that Shelley was a crude revolutionist, and believed that the overturning of kings and priests would regenerate mankind. I quoted the lines which tell how the halcyons ceased to prey on fish, and how poisonous leaves became good for food, to show that he foresaw more than any political regeneration, but was too timid to push the argument. I still believe that one cannot help believing him, as this scholar I know believes him, a vague thinker, who mixed occasional great poetry with a phantastic rhetoric, unless one compares such passages, and above all such passages as describe the liberty he praised, till one has discovered the system of belief that lay behind them. It should seem natural to find his thought full of subtlety, for Mrs. Shelley has told how he hesitated whether he should be a metaphysician or a poet, and has spoken of his 'huntings after the obscure' with regret, and said of that _Prometheus Unbound_, which so many for three generations have thought _Political Justice_ put into rhyme, 'It requires a mind as subtle and penetrating as his own to understand the mystic meanings scattered throughout the poem. They elude the ordinary reader by their abstraction and delicacy of distinction, but they are far from vague. It was his design to write prose metaphysical essays on the Nature of Man, which would have served to explain much of what is obscure in his poetry; a few scattered fragments of observation and remarks alone remain.