Another great tale from Chris Hitchens
On another occasion, he put his pipe in his mouth as he was ascending the subway steps. A policeman approached and told him that there was no smoking on the subway. Morgenbesser explained—pointed out might be a better term—that he was leaving the subway, not entering it, and had not yet lit up.
The cop repeated his injunction. Morgenbesser reiterated his observation. After a few such exchanges, the cop saw he was beaten and fell back on the oldest standby of enfeebled authority: “If I let you do it, I’d have to let everyone do it.” To this the old philosopher replied, “Who do you think you are—Kant?”
His last word was misconstrued, and the whole question of the categorical imperative had to be hashed out down at the precinct house.
(Source: vanityfair.com)