I once tried thinking for an entire day, but I found it less valuable than one moment of study.

Human nature is evil, and goodness is caused by intentional activity.

Thus, that one can find no place to walk through the breadth of the earth is not because the earth is not tranquil but because the danger to every step of the traveler lies generally with words.

Those whose character is mean and vicious will rouse others to animosity against them.

Human nature refers to what is in people but which they cannot study or work at achieving.

Quarreling over food and drink, having neither scruples nor shame, not knowing right from wrong, not trying to avoid death or injury, not fearful of greater strength or of greater numbers, greedily aware only of food and drink - such is the bravery of the dog and boar.

There are successful scholars, public-spirited scholars, upright scholars, cautious scholars, and those who are merely petty men.