A friend is nothing but a known enemy.

I like to complain and do nothing to make things better.

Tell nothing to thy friend which thy enemy may not know

I like to have strong opinions with nothing to back them up with besides my primal sincerity. I like sincerity. I lack sincerity.

Speak well of your friend, of your enemy say nothing.

And this was your friend?" Cordelia raised her eyebrows. "Seems to me the only difference between your friends and your enemies is how long the stand around chatting before they shoot you.