All our enemies are mortal.

Rivalry is the whetstone of talent.

Put national causes first and personal grudges last.

I tell you, there is such a thing as creative hate!

We often give our enemies the means for our own destruction.

It is very foolish to attack one’s enemy openly if one can injure him in secret.

One of the most time-consuming things is to have an enemy.

An injury is much sooner forgotten than an insult.

From hell’s heart I stab at thee; for hate’s sake I spit my last breath at thee.

To outwit an enemy is not only just and glorious but profitable and sweet.

Enemies are so stimulating.

Hoping for new friendship from old enemies is / Like expecting to find a rose in a furnace.

Many need no other provocation to enmity than that they find themselves excelled.