The abundance of land tended to prevent the development of industry, and the little industry which did exist was prevented by serfage from collecting in the towns.

But this explanation is evidently incomplete.

The same causes existed during the Middle Ages in Central Europe, and yet, in spite of them, flourishing cities grew up and played an important part in the social and political history of Germany.

In these cities collected traders and artisans, forming a distinct social class, distinguished from the nobles on the one hand, and the surrounding peasantry on the other, by peculiar occupations, peculiar aims, peculiar intellectual physiognomy, and peculiar moral conceptions.
Why did these important towns and this burgher class not likewise come into existence in Russia, in spite of the two preventive causes above mentioned?
To discuss this question fully it would be necessary to enter into certain debated points of mediaeval history.

All I can do here is to indicate what seems to me the true explanation.
In Central Europe, all through the Middle Ages, a perpetual struggle went on between the various political factors of which society was composed, and the important towns were in a certain sense the products of this struggle.