There are many ways to evaluate a theory. One can look for ambiguous or incomplete explanations, and those which are inconsistent or contradictory, and/or one can examine underlying assumptions and specific explanations and predictions and try to establish whether or not they are supported by evidence oneself and others can 'see", or, perhaps, at least agree seems to be "there". I have already attempted to do the former while presenting Marx's various theories of human nature. Here we take up the latter.