Department of Defense photo

Remember Donald Rumsfeld, Defense Secretary from 2001 to 2006? In response to a reporter’s question about weapons of mass destruction, he offered us valuable epistemological insight into known knowns, known unknowns, and unknown unknowns. Here’s a link if you have 35 seconds to enjoy a little history.

Mr. Rumsfeld never mention unknown knowns, with which investors often wrestle. Continue reading →