The key problem is to find out why that sector of society of...

The key problem is to find out why that sector of society of the past, which I would not hesitate to call capitalist, should have lived as if in a bell jar, cut off from the rest; why was it not able to expand and conquer the whole of society?... [Why was it that] a significant rate of capital formation was possible only in certain sectors and not in the whole market economy of the time?