Labor Theory of Value
The comment thread is, um, lively, and commenters tend to be smart and serious. A couple of themes stand out:
Marx was responding to a given, not an ideal situation. The holders of capital (and givers of jobs) had chosen the right parents.
Marx was writing from within the Classical Economic paradigm, before the new movement's refocus on the utility of the given economic system to the individual.
Brad's exposition of Marx ignores the dialectical method.
Marx accepted or was even for capitalism as a means towards an end.
Just a start, just a placeholder on this very dense debate on a subject I don't understand very well.