It is symbolling , the ability or tendency to symbol, i.e. use something arbitrarily to represent something that it is not, as an alphabetical writing system does. So, Hegel comes in that way. An opposable thumb is a necessary but not a sufficient condition for human being to emerge. It gives mind something to work with. That humans are social beings is also a necessary condition.
Communism is humanism.
They had more fully developed minds than their ancestors. Yea, the ability to symbol according to Geertz and Sahlins. So, you want to understand feudalism better so that you can understand capitalism better, in that you want to know how capitalism was latent or potential in feudalism. This gets to be a bit teleological, as Yoshie and Carrol might say. Capitalism was a potential in feudalism, but its actual historical occurrence was a dialectic of chance and necessity , contingency and teleology.