一个科学家的真正价值是由他思想的独创性和信念的勇气来衡量的。

True progress in farming means leaving the land better than we found it.

不要害怕与众不同，因为你是独一无二的。

The fountain of content must spring up in the mind, and they who have so little knowledge of human nature as to seek happiness by changing anything but their own dispositions will waste their lives in fruitless efforts.

习惯的强度与强化量成正比。