„Once he [Kafka] went to the Berlin aquarium … Suddenly he began to speak to the fish in their illuminated tanks, "Now at last I can look at you in peace, I don't eat you any more." It was the time that he turned strict vegetarian. If you have never heard Kafka saying things of this sort with his own lips, it is difficult to imagine how simply and easily, without any affectation, without the least sentimentality—which was something almost completely foreign to him—he brought them out. Among my notes I find something else that Kafka said about vegetarianism. He compared vegetarians with the early Christians, persecuted everywhere, everywhere laughed at, and frequenting dirty haunts. "What is meant by its nature for the highest and the best, spreads among the lowly people."“
— Max Brod
Franz Kafka: A Biography, translated by G. Humphreys Roberts and Richard Winston (New York: Schocken Books, 1960), p. 74.