Human nature is what Heaven supplies....

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.

A person is born with feelings of envy and hate. If he gives way to them, they will lead him to violence and crime, and any sense of loyalty and good faith will be abandoned.

In order to properly understand the big picture, everyone should fear becoming mentally clouded and obsessed with one small section of truth.

Youth is the gift of nature, but age is a work of art.

He who is of calm and happy nature will hardly feel the pressure of age, but to him who is of an opposite disposition youth and age are equally a burden.

The stars shall fade away, the sun himself Grow dim with age, and nature sink in years, But thou shalt flourish in immortal youth, Unhurt amidst the wars of elements, The wrecks of matter, and the crush of worlds.

To be happy, we must be true to nature and carry our age along with us.