Aesthetics is the branch of philosophy that deals with art, or more generally what the Oxford English Dictionary calls that of "taste, or of the perception of the beautiful" (see beautiful/sublime). The discipline in its modern form is primarily concerned with issues surrounding the creation, interpretation, and ultimate appreciation of works of art, and so it involves how the experience of such material is mediated through the individual sensitivity of the beholder, and the way the experience of it is shaped through presentation by cultural conventions such as the museum exhibition.
The term itself is derived from the ancient Greek aisthesis, meaning sensation or perception (see senses), in contrast to intellectual concepts or rational knowledge. Prior to the mid-eighteenth century, aesthetic inquiry was quite different from what it is today since there was no substantial concept of art as detached from trades or civic function. In Plato's time, questions concerned with the perception of beauty placed value with what promoted proper ethics and practically improved one's way of life. The Middle Ages saw opinions based on a variety of notions from theology (Aquinas) to optics (Witelo). There was a revival and focusing of such ideas and inquiry during the Renaissance, but they were most commonly focused on a particular genre (such as painting , sculpture , etc.), and not yet theorizing generally about the arts and their context. In 1735, a German philosopher, Alexander Baumgarten, was the first to use the word "aesthetics", in a work which defined beauty as perfection and stressed such information as gathered through the senses. However, it was Immanuel Kant's Critique of Judgment of 1790 that solidified the modern usage of the term, in which beauty became a subjective relation, not a property. As it concerns relatively recent media theory, Walter Benjamin and Marshall McLuhan discussed how the nature of such sense perception changes according to social circumstance. For instance, new kinds of media such as easily reproducible photography alter the function of works of art, as well as the way in which people view the world.
The new method of thinking about art based on Kant and the Romantics arose primarily in France, Germany, and Great Britain, due in part to philosophy's increased interest in sensory knowledge. Also, there was a new trend in cultural criticism that involved a wider scope, wherein different arts were compared to one another, and it was even argued whether or not one should compare them. Such developments were helped along by the fact that the eighteenth century was also a time when the public was given greater access to works of art, since they were no longer so exclusively linked to the government and the church. So it was a fruitful coincidence of the simultaneous changes in philosophy and art criticism that gave rise to this dual-role discipline in which art could be reasoned about broadly. Actually, the first century of the existence of aesthetics was marked by the disagreement over whether or not such generalizing was an advancement or not.
There exists a prevailing negative attitude towards aesthetics, even among those who work in related fields such as art history. Some do not acknowledge that it extends beyond the sphere of philosophy and into their own. Students of art sometimes have only a vague notion of what it is, based on the common use of "aesthetic" to mean "pleasing" or "beautiful", and the sense that it is archaic. Artists themselves do not usually appreciate what they see as categorization. It is possible that these groups are all under the misconception that aesthetics has not evolved since its beginnings, and that its basic goal is to promote the idea that there are certain universal truths about some supposed fixed characteristics of art. Such an idea is not compatible with the expanded definitions of art in the modern age. The truth, however, is that aestheticians are also against such rigid modes of thought, and have been involved in creating alternatives to such views ever since the inception of the discipline.
According to the Grove Dictionary of Art, there are four major subjects that are continually addressed by aesthetics. Often thought to be central is the question of what art is, how it can be defined. Some common opinions are that this depends on the effect it has on its audience, its place in society, how it was created, or whether or not it exhibits emotion (Tolstoy) or imitation (Plato and Aristotle). The borders between art and non-art are famously difficult ones to create, especially considering the wide variety of uses for the term, and the fact that our meanings for the term have altered so much in recent times. There are many inquiries however, which can be pursued without such a strict classification. Another large, classic area of discourse consists of whether aesthetic judgments can be thought of as objective or subjective. One view on this is that it is a matter of personal taste, determined by each individual's ideas or feelings. David Hume was a proponent of this idea, yet he stressed the need for experience with the type of thing being judged in order to make an informed decision. Others argue that this subjective model describes only the viewer's response, not the work itself, and that one can speak of facts about a work of art, as if there were a "science" of criticism. Next, the work of art critics such as Clement Greenberg or Michael Fried is concerned with the value of art- from individual pieces to the entire establishment. This involves whether a work is "good" or not, which examples are better or worse than others, and whether or not it is even possible to make such judgments. Morality and other types of value come into play here as well. Finally, issues arise around the importance of how works of art come into being, the extent to which what is not directly perceptible has relevance for the way we experience it. One theory is that art is basically communication from the artist, and the importance lies in what he or she meant by it; another focuses on what the work itself means, as based on an awareness of the conventions within which it was created. For example, Monroe Beardsley places worth solely with the detectable properties of a work itself, while Nietzsche and Croce emphasized the creative act, possibly independent of an audience, rather than the product.