It was not evident, they claimed, that the relations of production become "fetters" once the productive forces are capable of sustaining a different set of production relations. Likewise, Cornell political philosopher Richard W. Miller, while sympathetic with Cohen's analytical approach to Marxism, rejected Cohen's technological interpretation of historical materialism, to which he counterpoised with what he called a "mode of production" interpretation which placed greater emphasis on the role of class struggle in the transition from one mode of production to another. The Dutch philosopher Nicholas Vrousalis generalized Miller's critique, pointing out that Cohen's distinction between the material and social properties of society cannot be drawn as sharply as Cohen's materialism requires.