I never make exceptions. An exception disproves the rule. Winwood Reade is good upon the subject. He remarks that, 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 do, but you can say with precision what an average number will be up to.
Individuals vary, but percentages remain constant.
So says the statistician. I never guess. Inspector Gregory, to whom the case has been committed, is an extremely competent officer. Were he but gifted with imagination he might rise to great heights in his profession. One true inference invariably suggests others.