Great lecture by John Milios.
"Marx’s theory of value constitutes not a ‘modification’ or a ‘correction’ of Classical Political Economy’s theory of value, but a new theoretical domain, shaping thus a new theoretical object of analysis. Marx’s notion of value does not coincide with Ricardo’s concept of value as ‘labour expended’, but it constitutes a complex notion, a theoretical ‘junction’ which allows the deciphering of the capital relation, by combining the specifically capitalist features of the labour process with the corresponding forms of appearance of the products of labour. In this way, value becomes an expression of the capital relation and the Capitalist Mode of Production (CMP) emerges as the main theoretical object of Marx’s analysis."
http://users.ntua.gr/jmilios/LectureESF_Short.doc