Long or very important quotes are given a paragraph of their own with wider margins. This is distracting to the reader but this effect can be used to advantage. This special treatment means that no quotation marks are required. To repeat Fowler's [7] warning in its entirety:
A writer expresses himself in words that have been used before because they give his meaning better than he can give himself, or because they are beautiful or witty, or because he expects them to touch a cord of association in his reader, or because he wishes to show that he is learned or well read. Quotations due to the last motive are ill advised; the discerning reader detects it & is contemptuous; the undiscerning is perhaps impressed, but even then is at the same time repelled, pretentious quotations being the surest road to tedium; the less experienced a writer is, & therefore on the whole the less well read he is also, the more he is tempted to this error; the experienced knows he had better avoid it; & the well-read, aware that he could quote if he would, is not afraid that readers think that he cannot.