This chapter presents the sources on which John Stuart Mill drew when formulating his views on ratiocination and induction proper and analyzes their significance for his ideas on these matters. The sources that Mill consulted served as working tools that helped him develop a series of original ideas that reformed the study of logic. Induction is a kind of inference and could produce new knowledge, but, in the induction Mill got from Whately, a valid induction requires a uniformity principle that itself relies on induction. Mill defending the usefulness of the syllogism, even relying on it when he shows how induction depends on a uniformity principle. Yet, on the other hand, it shows denying its longstanding inferential significance. Whereas in the early editions of A System of Logic Mill was quite optimistic that his Canons of Induction would furnish the required rules on the basis of which indisputable inductive conclusions could be established.