In formulating his philosophy of aesthetics, George Santayana was both an original thinker and heavily indebted to earlier traditions in both philosophy and art. He aims for an approach that, he says, has so far been rare, one that is both “direct and theoretic.” He notes at the outset that one of the challenges in writing about beauty, in particular, is the high degree of subjectivity in its appreciation. He also sees this as a paradox in that people are inclined to trust in what they see around them as objective but are suspicious of their own creative output. Even in modern (in his time, the late 1800s) psychology, the focus has been on analyzing knowledge, which will help us understand the world outside us. He laments that this approach neglects imagination, which is perhaps even more important.

Man has a prejudice against himself: anything which is a product of his mind seems to him to be unreal or comparatively insignificant. We are satisfied only when we fancy ourselves surrounded by objects and laws independent of our nature.... The moderns, also, even within the field of psychology, have studied first the function of perception and the theory of knowledge, by which we seem to be informed about external things; they have in comparison neglected the exclusively subjective and human department of imagination and emotion.

Aesthetic value, for Santayana, is not the same as moral value. He phrases these areas as “the beautiful and the good.” Aesthetics tends to be subsumed within moral evaluations, however, as what is beautiful is often presumed to be good. A distinction he notes is that aesthetics is associated with immediate reactions or quickly made judgments, whereas morality looks ahead to the potential uses of the thing one regards, which constitutes a delayed judgment. When those judgments are applied to the aesthetic realm, they render it suspect because people are inclined to believe that enjoyment is sinful. Santayana believes, however, that because life is full of “dreadful evils” such as “death, hunger, disease, weariness, isolation, and contempt,” humans owe it to themselves to seek enjoyment.

The appreciation of beauty and its embodiment in the arts are activities which belong to our holiday life, when we are redeemed for the moment from the shadow of evil and the slavery to fear, and are following the bent of our nature where it chooses to lead us. The values, then, with which we here deal are positive; they were negative in the sphere of morality.

In addition to elaborating the principles of aesthetics, the author delves into the forms and materials that constitute both natural and manufactured things of beauty. He includes in this discussion the physiology of perception—how the eye processes what it sees. Among the areas he considers are geometric symmetry, landscape, and literature. He elaborates on the ways that random elements combine into aesthetically pleasing combinations, seeing this as creating an “intermediate effect” between the “sensuous delight” of “impressions” that we take in through our senses and the more intellectual understanding of “expression.” While he acknowledges that the possibility of the moral dimension applies, he also cautions against making this the dominant consideration.

There is an intermediate effect which is more mysterious, and more specifically an effect of beauty. It is found where sensible elements, by themselves indifferent, are so united as to please in combination....
If the object expressed by the form, and from which the form derives its value, had itself beauty of form, we should not advance; we must come somewhere to the point where the expression is of something else than beauty; and this something else would of course be some practical or moral good. Moralists are fond of such an interpretation, and it is a very interesting one....
But this theory is actually inadmissible. Innumerable aesthetic effects, indeed all specific and unmixed ones, are direct transmutations of pleasures and pains; they express nothing extrinsic to themselves, much less moral excellences.