The Twofold Labors of Marx challenges the common interpretation that Marx was right about capital, but wrong about work. Instead, Denning argues that Marx's theory of labor is just as important and insightful as his analysis of capitalism. In response, he proposes to turn Capital on its head—a deliberate inversion of Marx's own famous claim that he turned Hegel's dialectic "right side up." This means reconstructing Marx's work to highlight the labor theory that's embedded within it.
Denning argues we need to pay equal attention to the "circuit of labor", not just the circuit of capital; the "mystery of wages" not just commodity fetishism, and finally "Surplus population" theory and labor movements rather than just surplus value and capital movements. In other words, Marx developed a sophisticated dual analysis—examining both how capital accumulates and how labor is organized, transformed, and exploited.