Many kinds of relativism have been attributed to Karl Marx. We discuss three broad areas of Marx’s thinking: his theories of history, science, and morality. Along the way, we show that Marx is committed to a version of philosophical naturalism that privileges the results of genuine science over alternative ways of understanding the world. This outlook presupposes the possibility of objective knowledge of the world. It follows that Marx is no relativist (at least in the senses we consider). Unlike many (...) non-relativists, however, Marx pays close attention to the problems with which contemporary philosophers interested in relativism are most preoccupied: irresolvable moral disagreements between social groups, the evolution of institutions and practices over time, and the prominent, perhaps decisive role played by non-cognitive social factors in belief formation. We show how some later Marxists have mistaken this close attention for evidence that Marx himself is a relativist. (shrink)

Nell restricts cruelty to hominids, although good evidence suggests that secondary aggression in rodents and particularly primates may be considered cruel. A considerable literature shows that glucocorticoid secretion stimulated by stress facilitates learning, memory, arousal, and aggressive behavior. Either secondary aggression (to a conspecific) or increased affiliative behavior reduces stressor-induced activity, suggesting the reward system can be satisfied by other behaviors than cruelty.