Psychology should be the science of mental life, both of its phenomena and of their conditions.

我不害怕与众不同。

For every expert there is an equal and opposite expert, but for every fact there is not necessarily an equal and opposite fact.

The general will is always right， but the judgment which guides it is not always enlightened.

数学中最深刻的见解往往来自最抽象的理论。

我不是说唱歌手，我是一个改变思想的人。