Hobbes claimed that his political theory was a rigorously philosophical, that is, scientific, system. “[C]ivil philosophy/' he said, is “no older than my own book De cive ” (Wi,ix). Dedicating that work to the third earl of Devonshire, he argued that recent progress in science was largely the work of students of geometry, who had reasoned correctly from first principles. Moral philosophers, by contrast, had failed to adopt an adequate method, instead contenting themselves with winning the approval of their audiences by rhetorical devices designed to appeal to the emotions. He himself, however, had succeeded in grounding moral and political thinking upon firm foundations. He had begun his investigations, he said, by examining the nature of justice. Justice meant giving every man his own, and that raised the question of how things became one man's rather than another's. The answer, he concluded, was that nature taught people to shun the horrors that resulted from community of goods, and by consent to introduce private property.