Unlike many of Berlin's other books which are loosely grouped collections of essays, this book remains focused on the central theme of Romanticism. The book is essentially the written version of Berlin's 1965 Mellon lectures and there is a freshness to the pages, which were spoken, rather than written first (My copy came with a CD of the last lecture, which at last enabled me to put a voice to the writer). Berlin points out how Romanticism challenged the jigsaw puzzle concept of knowledge, in which it was assumed that there was an absolute knowledge which could be found, even if there were arguments over the ways and the people who could find it. Against this the Romantics, with their view of the creative will and there refusal to place structure on life tore up this concept and permanently altered modern European thought. In the last lecture Berlin connects Romanticism to what he considers to be examples of its heirs: existentialism and fascism. This is an impressive book, not least because Berlin is able to come up with an identifying theme of Romanticism, no easy task considering the diverse set of writers who have all been classified under its heading. His examination of Romantic writers mainly focuses on Germany, which he considers to have been the centre of Romantic thought. The book is easy to read and due to its source as a set of lectures contains almost no footnotes. While I enjoy almost all Berlin's writings I feel this one, virtually a transcription of lectures, is unlike his other works and while making serious and interesting points has great lightness and pace in its style.