In a courtroom a sharp lawyer can make any Res, including a ham sandwich,
ipsa loquor; but any decent historian will tell you that things do not
always speak for themselves. There is a marvelous account of George
Washington giving a visitor all the reasons why slaves could not be freed in
this country; but when you look at GW's documents you find that he had
already tried twice to free his slaves, and would actually do so in his
will. So his discussion with the visitor does not at all speak for itself.
Once again, I direct attention to Gregg Kimball's excellent posting on this
WPA subject back in March. 

Henry Wiencek