I can think of four distinct sources of pleasure that cause something to be considered aesthetically pleasing.
- Intellectual Engagement. Something, like a car is beautiful because it gracefully and economically fulfils its function. The beauty a thing has is based on three variables: one, the amount of complexity and quantity of parts; two, the integration and interconnection of these parts; and three, gracefulness and lack of arbitrary features that impede its purpose. The more complex, the more specialised, and the more efficient a thing is, the more beautiful we find it. This is the beauty that people find in machines and biological organisms. It can even be found (to a limited degree) in a well-shaped spoon.
- Emotional Expression. This is made by contrasting patterns, whose forms are emotionally charged. Different combinations of colour, texture, lines, and musical notes have emotional associations with them, because they replicate the physiological responses of emotions. If these are juxtaposed and contrasted with each other, more complex emotions may be expressed and these emotions may be recalled and manipulated in increasingly subtle ways. Contrast also emphasises the distinguishing features of patterns and prevents the mind from becoming numb to them. This aesthetic is most prominent in music, but it can be seen in decoration, especially in the classical and art-deco styles.
- Expressing a Lifestyle. Objects can be beautiful because they express a particular culture, environment, or lifestyle that we are either familiar with or wish to have. The object simply looks like something from the world that we wish we live in. Neuschwanstein castle is the purest example of this aesthetic in architecture. This form of beauty is commonly found in literature, drama, cinematography, landscapes, and rustic scenery. An object often acquires this aesthetic with age.
- Biological. This is an innate reaction to a particular stimulus. This is a very uncommon way to make aesthetic judgements. Usually this causes people to dismiss something as repulsive rather than praise its beauty. This can be identified when people personify objects: calling a house “cute” or describing a desk as “aggressive.” This is, however, almost the sole source of pleasure from the culinary arts. Like the other arts, it is assisted by contrast.
One theory in evolutionary psychology suggests that beautiful things are pleasing for the same reason that cheesecake is pleasing. It stimulates those parts of the brain that evolved thousands of years ago. Places and scenes that were healthy for our ancestors are pleasing because they provided an evolutionary advantage to our evolutionary ancestors.
This theory does not explain everything about aesthetics, but it is an interesting theory to consider.
In the general sense of the word “things” can be something concrete like art or an abstract entity akin to an idea. Regardless of form, as people with the gift of sight, we can see. The visual input is converted to a signal interpreted by the brain. If it is an unknown entity or unlike anything observed prior we may default to an emotional response. That reaction can vary in magnitude which potentially leads to pleasure. For any given individual the threshold for pleasure may vary due to age, experience, or context. If this “thing” is an known entity, any set of emotions may be expressed. A feeling of relief in seeing the familiar… immediate dislike for the representation differs in quality or construction… or even a blatant disregard if it seems forced.