"Normative science has three widely separated divisions: i. Esthetics; ii. Ethics; iii. Logic.
      … Ethics, or the science of right and wrong, must appeal to Esthetics for aid in determining the summum bonum. It is the theory of self-controlled, or deliberate, conduct." ('A Syllabus of Certain Topics of Logic', CP 1.191, 1903)

"…it is generally said that the three normative sciences are logic, ethics, and esthetics, being the three doctrines that distinguish good and bad; Logic in regard to representations of truth, Ethics in regard to efforts of will, and Esthetics in objects considered simply in their presentation." (Harvard Lectures on Pragmatism, CP 5.36, 1903)

      "Supposing, however, that normative science divides into esthetics, ethics , and logic, then it is easily perceived, from my standpoint, that this division is governed by the three categories. For Normative Science in general being the science of the laws of conformity of things to ends, esthetics considers those things whose ends are to embody qualities of feeling, ethics those things whose ends lie in action, and logic those things whose end is to represent something." (Harvard Lectures on Pragmatism, CP 5.129, 1903)