人类社会生活的行为流是由存在的物质条件构成的。

财产权确实是人类的一项权利，与自由一样真实。

描述自然景色，也暗喻人应顺应自然。

The greatest obstacle to being heroic is the doubt whether one may not be going to prove one's self a fool; the truest heroism is to resist the doubt; and the profoundest wisdom, to know when it ought to be resisted, and when to be obeyed.