Digital Companion to C. S. Peirce
1903 | A Syllabus of Certain Topics of Logic | CP 1.191

Normative science has three widely separated divisions: i. Esthetics; ii. Ethics; iii. Logic.

Esthetics is the science of ideals, or of that which is objectively admirable without any ulterior reason. I am not well acquainted with this science; but it ought to repose on phenomenology.

1903 | Harvard Lectures on Pragmatism: Lecture I | CP 5.36

…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.

1903 | Harvard Lectures on Pragmatism: Lecture V | CP 5.129

…As for esthetics, although the first year of my study of philosophy was devoted to this branch exclusively, yet I have since then so completely neglected it that I do not feel entitled to have any confident opinions about it. I am inclined to think that there is such a Normative Science; but I feel by no means sure even of that.

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.

1904 | A Brief Intellectual Autobiography by Charles Sanders Peirce | Peirce, 1983, p. 71; MS [R] L107:19-20

…philosophical esthetics (which becomes something very different from the study which the noun usually designates)[,] studies the characters which will belong to the phenomenon so far as it is controllable, that is, the characters of what is aimed at. Thus, the question, What is the summum bonum, is regarded as an esthetical question.

1904 | Reason's Conscience: A Practical Treatise on the Theory of Discovery; Wherein logic is conceived as Semeiotic | NEM 4:192; HP 2:826

Esthetics is that normative science which studies the conditions of that kind of excellence which objects may possess in their presentation, or appearance, regardless of their relations.

nd | On Classification of the Sciences | MS [R] 602:11

My notion is that there is a study of esthetics, not the exclusive pleasure-ground of those who spend their lives in the delights of art, nor yet particularly considering conduct, but a study to make out what it is wherein the fine, the adorable, the noble, is such.

nd | A Suggested Classification of the Sciences | MS [R] 1339:12

…self-control depends upon the comparison of what is done with an ideal admirable per se, without any ulterior reason. Now the science of that which is admirable without an ulterior reason is Esthetics.