[1] The book was published in 1896 by Charles Scribner's Sons, and is based on the lectures Santayana gave on aesthetics while teaching at Harvard University.

"[1] The Sense of Beauty is subdivided into a preface, an introduction (The Methods of Aesthetics), four main parts, and a conclusion.

Santayana rejects the notion of disinterestedness as defining property, because he sees one sense of disinterestedness in pleasure, because pleasure ″is not sought with ulterior motives [...] but [with] the image of an object or event stuffed with emotion.″(§8) Santayana derives his main definition of beauty from what he calls ″psychological phenomenon, viz., the transformation of an element of sensation into the quality of a thing″, and with repeated exposure, only a small subset of sensations remains to be regarded as ″quality″ of the object (§10).

First, Santayana claims that pleasures derived from all human functions may become objectified and hence the material of beauty, albeit this is most easily done in the cases of vision, hearing, memory and imagination (§12, §18).

He describes sight as "perception par excellence" and form as usually visual experience to be "almost a synonym of beauty" (§17).

Santayana states that touch, taste, and smell are less likely to lead to "objectified" pleasure, because they ″remain normally in the background of consciousness" (§15).

Santayana notes that sensuous material a) is necessary for finding or creating beauty (how else could one perceive the poem, building, etc.

He starts by emphasizing that it is only in their combination that sensual elements are able to please (§19) and he directly relates this pleasure to being conscious of the physiological processes underlying them (§21).

He identifies symmetry (§22) and a balance between uniformity and multiplicity (§23-24) as eliciting such a pleasing perceptual experience; as an example he uses the beauty one finds in the stars (§25).

Santayana here also introduces the concept of ″indeterminate″ objects that are in some way vague or incoherent and thus require and allow the observer to further interpret it (§32), such as landscapes (§33).

Even though digressions from his main topic, Santayana in this chapter reveals a number of thoughts and insights that mirror parts of later scientific theories: Santayana devotes the last part of his book to the qualities that an object acquires indirectly by means of associations, (such as with other concepts and memories), which he calls "expression" (§48).

[8] The German philosopher Ernst Cassirer criticized Santayana's characterization of art as "the response to the demand for entertainment" in contrast to science which seeks to deliver truthful information.

Cassirer called Santayana's position "aesthetic hedonism" and refused its idea (as he understood it) that art is merely entertainment.