Inference and Norm : On the Art of Life and its Structure in J.S.Mill's "A System of Logic"

In this paper, I argue about "the logic of practice" that J.S.Mill treated in the last chapter of "A System of Logic". The logic of practice, which is also called "the art of life", is referred as his ethical perspective by many scholars. Nevertheless, its position in "A System of Logic" itself tends hardly to be discussed. They are liable to overlook that "the art of life" is an important part of "A System of Logic" and closely related to the other parts of this work. Therefore, I will examine what is the structure of theinference that Mill stated mainly in Book.II and how it is used in the art of life. Here are derived the following consequences. Mill's syllogism is characterized as a passage "from particulars to particulars" . This inference is employed in the art of life that is the inference in an imperative mood, in the same way as is done in scientific inference in an indicative mood. Moreover. "narrow sense induction" is characterizedas a passage "from particulars to generals ", while "ratiocination" as a passage "fromgenerals to particulars". In the art of life, the former is used as "the art of the legislator" and the latter as "the art of the judge". Finally, by both operations, rules of our life are progressively improved