According to his early biographers, at a certain point in his life Kant had a ‘maxim’ not to smoke more than a single pipe a day, tempted though he was. He adhered to this maxim rigorously. After a while, however, he bought a bigger pipe.

Jens Timmermann, Kant, in Sacha Golob and Jens Timmermann (eds.) The Cambridge History of Moral Philosophy, 2000, pp. 394–409, p. 39