We conclude that the concentration of wealth is natural and inevitable, and is periodically alleviated by violent or peaceable partial redistribution. In this view all economic history is the slow heartbeat of the social organism, a vast systole and diastole of concentrating wealth and compulsive recirculation.
–Will and Ariel Durant, from their 1968 book The Lessons of History

The tone is characteristic of the Durants: sweeping, aphoristic, morally neutral, and deliberately cyclical rather than progressive. They’re not endorsing either concentration or redistribution. They’re arguing that the oscillation itself is the pattern, and that societies which manage the redistribution peacefully (through law and taxation) fare better than those that let the pressure build until it explodes in revolution.