Nature and wisdom never are at strife.
Plutarch

It is easier to be wise for others than for ourselves.
Francois De La Rochefoucauld

The art of being wise is knowing what to overlook.
William James 

Years teach us more than books.
Berthold Auerbach

The wisdom of nations lies in their proverbs,
which are brief and pithy.
William Penn

The middle course is the best.
Cleobulus

The only medicine for suffering, crime, and all the other woes of mankind, is wisdom.
Thomas Huxley

A wise man learns by the mistakes of others,
a fool by his own.
Latin Proverb

Silence does not always mark wisdom.
Samuel Taylor Coleridge.

The seat of knowledge is in the head, of wisdom,
in the heart.
William Hazlitt