While the individual man is an insoluble

While the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty.  You can, for example, never foretell what any one man will be up to, but you can say with precision what an average number will be up to.  Individuals vary, but percentages remain constant.  So says the statistician.  ~Arthur Conan Doyle, "The Sign of the Four," The Complete Sherlock Holmes; NA