This chapter describes quantification during the late nineteenth century. Then, most ordinary people were gaining an overt awareness, and probability notions were seeping into everyday conversation and decision-making. However, new forms of abstract mathematics were being developed, albeit with some opposition from Lewis Carroll (Charles Dodgson), who wanted to preserve traditionalist views of Euclidian geometry. The chapter introduces William Gossett, who worked in the laboratory of the Guinness brewery and developed “t-distribution,” which was published as “Student’s t-test.” It also describes his friendship with Sir Ronald Fisher, who developed many statistical hypothesis testing methods, published in The Design of Experiments, such as the ANOVA procedure, and the F ratio. Fisher also developed many research designs for hypothesis testing, both simple and complex, including the Latin squares design, as well as providing a classic description of inferential testing in the thought experiment called “the lady tasting tea.”