" Despite the massive intellectual feat that Marx's Capital represents, the Marxian contribution to economics can be readily summarized as virtually zero. Professional economics as it exists today reflects no indication that Karl Marx ever existed. This neither denies nor denigrates Capital as an intellectual achievement, and perhaps in its way the culmination of classical economics. But the development of modern economics had simply ignored Marx. Even economists who are Marxists typically utilize a set of analytical tools to which Marx contributed nothing, and have recourse to Marx only for ideological, political, or historical purposes.

In professional economics, Capital was a detour into a blind alley, however historic it may be as the centerpiece of a worldwide political movement. What is said and done in its name is said and done largely by people who have never read through it, much less followed its labyrinthine reasoning from its arbitrary postulates to its empirically false conclusions. Instead, the massive volumes of Capital have become a quasi-magic touchstone—a source of assurance that somewhere and somehow a genius "proved" capitalism to be wrong and doomed, even if the specifics of this proof are unknown to those who take their certitude from it. "

― Thomas Sowell , Marxism: Philosophy and Economics