This collection of primary sources examines scientific methodology in Britain during the long nineteenth century. The nineteenth century played host to the development, for the first time, of statistical and probabilistic methods across the biological, human, and social sciences. A new kind of quantified, statistical social science came into being. Such innovations were quickly marshaled for use in the life sciences, from evolution to agriculture to eugenics. This title will be of great interest to students of the history of philosophy and the history of science.