" Probit analysis provides a mathematical foundation for the doctrine first established by the sixteenth-century physician Paracelsus: “Only the dose makes a thing not a poison.” Under the Paracelsus doctrine, all things are potential poisons if given in a high enough dose, and all things are nonpoisonous if given in a low enough dose. To this doctrine, Bliss added the uncertainty associated with individual results. One reason why many foolish users of street drugs die or become very sick on cocaine or heroin or speed is that they see others using the drugs without being killed. They are like Bliss’s insects. They look around and see some of their fellow insects still alive. However, knowing that some individuals are still living provides no assurance that a given individual will survive. There is no way of predicting the response of a single individual. "

― , The Lady Tasting Tea: How Statistics Revolutionized Science in the Twentieth Century