We must ask questions because we must have tremendous doubt. That doubt must be held on a leash, otherwise doubt will not do anything – you must know when to doubt and when not to doubt. But you must begin by doubting everything to find out when not to doubt. It is like cooperation: you must know what it means to cooperate completely, and only then will you know when not to cooperate.
From a Public Talk in Florence, Italy, 29 October 1970