The Cambridge History of English and American Literature in 18 Volumes (1907–21).
Volume XI. The Period of the French Revolution.
§ 5. The Friend; Biographia Literaria
The strangest thing is that, in the very height of the opium fever, he should have been capable of efforts which, though lamentably unequal, still gave evidence of powers which not one of his contemporaries could have rivalled. It was between 1808 and 1815 that he delivered the bulk of the critical lectures which make an era in the history of English literary criticism; that he composed The Friend, in its earlier and, doubtless, far inferior version (1809); and, finally, that he wrote all save a few passages of Biographia literaria (1815), the only one of his prose works which can be said to survive to the present day. Even in the depth of his debasement, he must have retained an amazing spring, a power of throwing off weights which would have crushed another man, of recovering something, at any rate, of the free flight to which he was born. It was this boundless power of self-retrieval that, at length, enabled him to cast off the yoke of opium. It was this, even more than his genius, which drew men to him as a magnet and never allowed him to forfeit the admiration, and even the respect, of his friends.
The work of Coleridge naturally falls under three heads: poetry, criticism and philosophy. It remains to attempt a brief estimate of each.