With a solar powered sail and using the sun and wind to power the batteries, the purpose of the mission is to show that renewable energy works.

VOA: standard.2009.12.10

We usually think of individual freedom and security as the purpose of the separation of power.

我们通常认为,个人自由与安全,是分权的目的。

耶鲁公开课 - 政治哲学导论课程节选