"At almost the first meeting I attended, a dispute broke out between Quine and Aiken. The year before, apparently, one of Quine=s doctoral student working jointly in Mathematics and Philosophy had been permitted to substitute one of the Mathematics qualifying examinations for the Preliminary Exam on Ethics. Now one of Aiken's students, working jointly in Philosophy and Art History, wanted to substitute an Art History exam for the Logic Prelim. Quine said flatly that it was out of the question. Aiken protested that by parity of reason [ordinarily a winning move in philosophical arguments] he should be allowed to make the substitution. Quine was adamant. Finally Aiken turned to Quine and said, "All right, Ledge, why not? What is the difference between Ethics and Logic." "The answer is simple," Quine replied. "Ethics is easy and Logic is hard." Aiken was apoplectic but the substitution was disallowed."