WIST

A wise man gets more use from his enemies than a fool from his friends.

Baltasar Gracián y Morales (1601-1658) Spanish writer.
The Art of Worldly Wisdom #84 (1637)

It is better to sleep on things beforehand than lie awake about them afterwards.

Baltasar Gracián y Morales (1601-1658) Spanish writer.
The Art of Worldy Wisdom #151 (1637)

Never contend with a man who has nothing to lose.

Baltasar Gracián y Morales (1601-1658) Spanish writer.
The Art of Worldy Wisdom #172 (1637)
Source: http://www.dantaylor.com/books/gracian.html

Many would be wise if they did not think themselves wise.

Baltasar Gracián y Morales (1601-1658) Spanish writer.
The Art of Worldy Wisdom #176 (1637)

Never open the door to a lesser evil, for other and greater ones invariably slink in after it.

Baltasar Gracián y Morales (1601-1658) Spanish writer.
The Art of Worldy Wisdom #31 (1637)

Without courage, wisdom bears no fruit.
[Alt: Knowledge without courage is sterile.]

Baltasar Gracián y Morales (1601-1658) Spanish writer.
The Art of Worldy Wisdom #4 (1637)