The might have been

In history there are no control groups. There is noone to tell us what might have been. We weep over the might have been, but there is no might have been. There never was. It is supposed to be true that those who do not know history are condemned to repeat it. I don't believe knowing can save us.

Cormac McCarthy, All The Pretty Horses (Picador, 2010) p. 245