发愤研究学问，常常忘记吃饭，一旦有所收获便又高兴地忘记了忧愁，连自己的渐趋衰老也没有感觉到。

Psychology is concerned with the what and how of mental life, not the why.

一本书是作者和读者之间的对话，一种超越时间和空间的对话。

The power of the legislative being derived from the people by a positive voluntary grant and institution, can be no other than what that positive grant conveyed, which being only to make laws, and not to make legislators, the legislative can have no power to transfer their authority of making laws to any other hands.