 Cohen accepts that Marx’s theory makes some large and controversial claims, but comes to think that these may be less demanding than is often thought. Cohen distinguishes two interpretations of historical materialism. On an inclusive reading, the theory claims that material and economic developments explain the principal features of other, non-economic developments. However, on a restricted reading, the theory commits itself to explaining non-economic phenomena only when, if they weren’t so explained, they would seem to control material development. The theory, on this “restricted” reading, limits itself to explaining non-economic phenomena which possess “economic relevance” (G. Cohen 1988: 173). It seems likely that Marx and Engels—perhaps under the influence of Hegel’s philosophy of history—assumed an inclusive reading, but Cohen suggests that the restricted reading is consistent with the “1859 Preface”, and may offer a better fit with historical evidence.