Rules I've broken...

[lknbne]

Edwin Markham:

He drew a circle that shut me out --
Heretic, rebel, a thing to flout.
But love and I had the wit to win:
We drew a circle that took him in.

John F. Kennedy:

Forgive your enemies, but never forget their names.

Thomas Jefferson:

An enemy generally says and believes what he wishes.

Edward Hubbard:
Never explain -- your friends do not need it and your enemies will not believe you anyway.