Shelley was eighteen when he wrote "Queen Mab"; he never published it. When it was written, he had come to the decision that he was too young to be a 'judge of controversies'; and he was desirous of acquiring 'that sobriety of spirit which is the characteristic of true heroism.' But he never doubted the truth or utility of his opinions; and, in printing and privately distributing "Queen Mab", he believed that he should further their dissemination, without occasioning the mischief either to others or himself that might arise from publication. It is doubtful whether he would himself have admitted it into a collection of his works. His severe classical taste, refined by the constant study of the Greek poets, might have discovered defects that escape the ordinary reader; and the change his opinions underwent in many points would have prevented him from putting forth the speculations of his boyish days. But the poem is too beautiful in itself, and far too remarkable as the production of a boy of eighteen, to allow of its being passed over: besides that, having been frequently reprinted, the omission would be vain. In the former edition certain portions were left out, as shocking the general reader from the violence of their attack on religion. I myself had a painful feeling that such erasures might be looked upon as a mark of disrespect towards the author, and am glad to have the opportunity of restoring them. The notes also are reprinted entire--not because they are models of reasoning or lessons of truth, but because Shelley wrote them, and that all that a man at once so distinguished and so excellent ever did deserves to be preserved. The alterations his opinions underwent ought to be recorded, for they form his history.