There’s no sense in being precise when you don’t even know what you’re talking about.
John Von Neumann
That seems like the perfect condemnation for his book on quantum mechanics.
This is also the guy who said "Young man, in mathematics you don't understand things. You just get used to them." Wikipedia says that what the young man didn't understand is the method of characteristics, which sounds like it should be understood, from what little I know about it.
Do you have a source or context for this quote?
A monthly thread for posting any interesting rationality-related quotes you've seen recently on the Internet, or had stored in your quotesfile for ages.