Q: What do you think of the old saying, “It takes one to know one”?
A: It’s a package deal. By package deal I mean the lumping of a true concept with a false one. The evil of a package deal is that the truthful part of the statement motivates one to accept the full statement, which is false.
The true part of the statement: People who possess a certain quality — especially a really bad one, such as deceitfulness — are quick to see this quality in others. Psychologists sometimes call this projection. I’m not much for conventional psychology, but I must say that I see evidence of projection all the time. Husbands cheating on their wives are quick to see deceit in their wives’ behaviors, even if the wife’s behavior is nothing more than arriving home 15 minutes late from the grocery store. People guilty of a certain action often accuse another of that very same action; it seems to calm their guilt and help them pretend that they’re innocent.
The false part of the statement: Just because you recognize a quality in someone doesn’t mean you possess it. The most honest person in the world is capable of recognizing deceit in another, because lying is self-evidently what it is. If you catch me in a lie and then I say to you, “It takes one to know one,” you would rightly dismiss my claim as arbitrary and ridiculous. This old saying can serve to undercut confidence in one’s capacity for making honest, objective moral judgments. Because such judgments are a necessary and crucial part of life, I completely reject it.
So the old saying, “It takes one to know one” is half true, half false–putting it into the category of a vicious falsehood, a package deal worse than a garden variety falsehood. Half a truth is actually worse than no truth at all.