Compared with other scientists of the nineteenth century, the German chemist Justus von Liebig (1803–73) was a complex figure. In part, this was because Liebig established such broad borders for his science. Chemical methods, popular and professional publications about chemistry, technological applications, promoting the car and even politics – all were central concerns stemming from Liebig's notion of chemistry as the central science.

When Liebig discovered John Stuart Mill's Logic, a work on the philosophy of science, it struck a deep chord within him. Mill's high praise for Liebig's chemistry certainly provided Liebig with a means to promote his own reputation. In addition, Mill's Logic presented science as a central method for the general reform of society, a goal Liebig was himself struggling to define in the early 1840s. In the scientific method, Mill discovered a ‘rule by the elite’, which he could never find nor justify in his political philosophy. This was a rule that greatly appealed to Liebig, and he set out to ensure that Mill's work was translated and published in German. Though many details of this transaction are known, this paper seeks to investigate the relationship between Liebig and Mill's book, and the significance of this relationship for understanding Liebig's role as a gatekeeper and inter-relations between science and politics.