There's not much else to say about that.
Religion and the development and institutionalization of war are two topics that come to mind, relative to that assertion.
Just beacuse something can't be proven doesn't mean it's not true. Also, ust because something can't be measured doesn't mean it's not worth doing. Just because a project can't be quantified, we can't put an exact dollar figure and timeline to it -- that doesn't mean it's not worth trying.
Just because someone can't be "managed" doesn't mean he's not worth employing? Yeah.
Sometimes risks succeed. And if you stick only with the totally safe, you will succeed only to the level that everyone else does. (And even then, you may fail regularly -- because the "totally safe" isn't, and everyone else is dumb.)
Well, there. I found some more to say about it.