Abstract
The project of developing a theoretically rigorous and fruitful historical materialism, launched by G. A. Cohen in the late 1970s, led to a wealth of new directions: concept clarification, various new proposals for substantiating productive forces primacy and directionality, and much work on specific historical periods, especially the English/Western European transition to capitalism. All of this needs to be re-integrated into a general theoretical framework, one that both captures the common core in social evolution, and elucidates the rich variety of forms and experiences in which that core is embodied. Directedness and necessity in historical transformation do not contradict or undermine agency, specificity and cultural variety; on the contrary, they enable us to make full use of the vast array of possibilities in the service of progress