I've always liked Marx's comment suggesting that Mill's coop socialism attempted to 'reconcile irreconcilables'...
'The Continental Revolution of 1848 also had its reaction on England. Men who still claimed scientific importance and wanted to be more than mere Sophists and sycophants of the ruling classes, sought to harmonize the Political Economy of capital with the claims of the proletariat, now no longer to be ignored. Hence an insipid syncretism, as best represented by John Stuart Mill.' (from postscript to second German ed. of Capital, excerpted in _Karl Marx: On History & People_, Saul Padover ed/trans, p. 254)
Michael Hoover