Dear John, 

I have decided that I can no longer see you. Our relationship has ended, and I wish you well in your future.

Good-bye,

Jane

Whether you've ever written or received a "Dear John" or "Dear Jane" letter, the basic outline and intent is clear. It begins with a basic greeting — not "Dear Johnny" or "Sweetheart" or some other form of endearment, but simply "Dear John." There is a very brief and to-the-point body of the letter that makes it clear the relationship is over. Then the letter writer signs off with his or her own name. The "Dear John" or "Dear Jane" letter is a variation on the standard letter format used in other personal letters and even business correspondence today. Each letter has a clear beginning, a middle, and an end.

In the ancient world, letters also tended t…