John Radford ("Precise definitions", Letters, 2 August) is correct in his general thesis. However, his example of the slight contretemps between Holmes and Moriarty at the Reichenbach Falls ("The Final Problem", 1893) is somewhat premature in its judgement. Some 120 years after the (alleged) incident, the jury still appears to be out as to who, if anyone, was the "nemesis" of whom.
We are not helped on such serious matters by the ambivalence of Sir Arthur Conan Doyle.
Iain Smith, Honorary fellow, University of Strathclyde