The answer to this question is a difficult one, and a closer consideration of the arguments in the literature is necessary for a full answer than can be given in this article. However, it is worth bearing in mind that Cohen had previously been committed to the strict view that human nature (and other 'asocial premises') were sufficient for the development of the productive forces - it could be that they are only one necessary constituent. It is also worth considering that by 1988 (see quotation above), he appears to consider that the problem is resolved.