There are more people who can work to increase the production, but beyond that point there are more people to feed than the production can produce, and that leads to a desire for expansion of the land available for cultivation.

越来越多的人从事工作,生产力得以提高,但是一旦突破临界值,花费就要超过所得了,它导致了对土地扩张的需求

耶鲁公开课 - 古希腊历史简介课程节选