Vol. 18 of the Collected Works, besides including the consolidated index to the Collected Works as a whole, contains two substantial supplements: a long and important critique on Freud written in the last weeks of Elias' life, not previously published in English; and an essay, not previously published in any language, on the anthropologist-philosopher Lucien Levy-Bruhl and the problem of 'the logical unity of humankind'. Both essays fill important gaps in Elias' work, and deal with common criticisms of his thought.