As for the labor theory of value. I don't know whether it explains everything; but it explains the things that are important now. Joanna ======
It explains capitalism _as a whole_, as a completed system. But I'm not sure what you think it explains. It doesn't hold up empirically as an explanation of prices or wages. And it's not needed to explain exploitation, which has been an obvious fact for several millennia longer than capitalism has existed.
I would tend to agree with Postone that a critique of political economy is NOT the same as a critical political economy. And there is no such thing as a "science" (under any definition) of economics. The separation of state and economy calls for _historical_ explanation. Her grasp of that is what makes Ellen Meiksins Wood the most important Marxist writing in English.
Carrol