Professor Heisenberg (pontifically): Ignorance is now included amongst the Laws of Science. The behaviour of an electron, for example, involves the Principle of Uncertainty.
Myself (incredulously): What? You surely don't mean objectively?
Prof. H. (a little surprised): Why not? An electron, we discover, is, by nature, uncertain. That is perfectly objective.
Myself (with heavy sarcasm): An electron really is uncertain! I suppose you are going to tell me that you can read an electron's mind.
Prof. H. (quite unmoved): Of course. How else should we know that it was uncertain?
Myself (completely taken aback): Read an electron's mind? How?
Prof. H. (expansively): Perfectly simple. The mind, as we all know, is the nervous system; and, as the latest and most scientific authorities assure us, we can always discover the state of the nervous system by observation and study of behaviour patterns. All we have to do, then, is to observe an electron and deduce from its behaviour how its nervous system is; and we have discovered, in fact, that it is indeterminate. We are thus able to say that an electron cannot make up its mind.
Myself (fascinated): Yes! Yes! Of course!
Prof. H. (with finality): So you see, an electron is uncertain, just as we may observe that Schmidt is phlegmatic or that Braun is choleric or that you, my dear friend, are, if I may be permitted to say so, a little psychopathic. And what could be more objective than that?
23 August 1957
(from letter to Ven. Nanamoli)