“The material which he wrote between October 1857 and June 1858, i.e. the bulk of the ‘Grundrisse’, has been called the ‘centrepiece of Marx’s thought’, and in some ways, the best and ‘completest’ of all his works. (Mc Lellan (1971a), 3, 15). Why, when Marx set to work in October 1857, did he work so hard and so well? Without testimony from Marx himself it is impossible to discover exactly why his work improved and expanded so suddenly. The trade crisis of October 1857 is usually cited in connection with the increased pace of his work, since he mentioned in a letter to Lassalle of 21 December 1857 that it had ‘spurred me to work seriously on my ‘Principles of [Political] Economy’, also to prepare something on the present crisis’ (MEW XXIX, 548). But Marx had predicted or experienced trade crises in 1850, 1851, 1852, 1853, 1855, 1856, and the spring and summer of 1857, and he had managed to do ‘some’ work on political economy during those years (at least twenty-four notebooks and two unfinished manuscripts) in spite of his appalling circumstances. Poverty, ill-health, and journalism continued unabated through 1857 and 1858, and yet he wrote the ‘Grundrisse’. Any number of things may have facilitated the dramatic change in the quantity and quality of his work, but the methodological innovations of the ‘Introduction’ of August/September 1857, written just before the great burst of activity which began in October, probably play a large part in the explanation” [Terrell Carver, ‘Marx’s Introduction (1857) to the Grundrisse der Kritik der politischen Ökonomie’ (Editor’s Preface)] [Karl Marx, a cura di Terrell Carver, Texts on Method, 1975]