Asimov's wide interests included his participation in his later years in organizations devoted to the comic operas of Gilbert and Sullivan  and in The Wolfe Pack,  a group of devotees of the Nero Wolfe mysteries written by Rex Stout . Many of his short stories mention or quote Gilbert and Sullivan.  He was a prominent member of the Baker Street Irregulars , the leading Sherlock Holmes society,  for whom he wrote an essay arguing that Professor Moriarty's work "The Dynamics of An Asteroid" involved the willful destruction of an ancient civilized planet. He was also a member of the all-male literary banqueting club the Trap Door Spiders , which served as the basis of his fictional group of mystery solvers, the Black Widowers .  He later used his essay on Moriarty's work as the basis for a Black Widowers story, " The Ultimate Crime ", which appeared in More Tales of the Black Widowers .  
Asimov took varying positions on whether the Laws were optional: although in his first writings they were simply carefully engineered safeguards, in later stories Asimov stated that they were an inalienable part of the mathematical foundation underlying the positronic brain. Without the basic theory of the Three Laws the fictional scientists of Asimov's universe would be unable to design a workable brain unit. This is historically consistent: the occasions where roboticists modify the Laws generally occur early within the stories' chronology and at a time when there is less existing work to be re-done. In "Little Lost Robot" Susan Calvin considers modifying the Laws to be a terrible idea, although possible,  while centuries later Dr. Gerrigel in The Caves of Steel believes it to be impossible.