A real friend or mentor isn't on your payroll.

A good friend who points out mistakes and imperfections and rebukes evil is to be respected as if he reveals the secret of some hidden treasure.

If friends disappoint you over and over, that's in large part your own fault. Once someone has shown a tendency to be self-centered, you need to recognize that and take care of yourself; people aren't going to change simply because you want them to.

I distrust the wisdom if not the sincerity of friends, who would hold my hands while my enemies stab me.

Compliments win friends, honesty loses them.

Friends make pretence of following to the grave but before one is in it, their minds are turned and making the best of their way back to life and living people and things they understand.