Traditionally, the domain of aesthetics is thought to be the same as the sphere of art. Minor conceptual tensions due to, say, the presence of an aesthetic element in our everyday experiences far from any artistic creativity are readily removed by the speculations about embedding art into common life as the principal goal of aesthetic education. Well, in a way, such a treatment is reasonable enough and acceptable in many practical cases. However, we still need to explain the difference.
Typically, aesthetics is said to refer to the perception (feeling, sense) of art, as the very name suggests. In that context, the term "art" is to stress the active, creative side of the same. In a more general manner, one could speak about the reflection of art as a special activity different from art itself. This reflection may include both syncretic experience and all kinds of analytical attitude. In particular, the nature of art can be expressed in the form of art, as well as in scientific notions and philosophical categories. This means that, at least, aesthetics is not a branch of philosophy, nor a science about art, as they often say; farming aesthetics out to the introspection of the artists seems even less justified. It is certainly wider, allowing for all these partial manifestations.
A similar situation could be observed with logic, which is commonly believed to refer to the method of scientific work (often reduced to sheer rationality), and ethics, traditionally restricted to explaining our moral choices. This suggests the idea of commonality of all such modes of reflection, and hence the necessity of categorical distinction.
Considering the hierarchical structure of reflection in respect to its product, we arrive to distinguishing its syncretic, analytical and synthetic levels. Syncretic reflection is "embedded" in any non-reflective activity, comprising any perceptual sets, traditional views and beliefs, public opinion, common sense judgment, etc. On this level, the product of reflection (the spiritual side of the culture) is not separated from the subject and is directly implemented in the modes of activity. On the contrary, analytical reflection is aimed at producing specially designed things (objects) representing the modes of conscious activity; such artifacts do not need to be of any practical value beside their representative function. This level of reflection obviously includes art, science and philosophy; one could argue that these are its fundamental sublevels, and any other forms of analytical reflection must refer to the same hierarchy taken in a different position (in the sense of hierarchical conversion). Now, we are left with the only choice for the kind of reflection related to aesthetics, logic and ethics; namely, the synthetic level of reflection. The "imperative" flavor of such evaluative phenomena is thus immediately explained, since synthetic reflection is a kind of pathway from reflection to praxis, and its primary purpose is to transform the abstract analytical product into practical recommendations. The synthetic character of the reflective product means that, like on the analytical level, this product is recognizable as separate from mere modes of common activities, but, on the other hand, it can only be implemented in the schemes of specific activities, thus returning reflection to the original syncretism.
Using the old Hegel's triad, one could relate the levels of reflective activity (as a cultural phenomenon) to the levels of subjectivity: consciousness, self-consciousness and reason. In particular, synthetic reflection is to provide reasons for our practical acts.
In this context, aesthetics becomes a complex hierarchical formation, including the levels of aesthetic perception, aesthetic creativity and aesthetic judgment. It is not necessarily concerned with the works of art, just like logic does not only pertain to science and ethics is in no way a prerogative of moralizing philosophers. On the synthetic level, the very distinction between the possible forms becomes relative; in fact, here, such distinctions are mainly due to the target application rather than the inner complexity of reflection. It may be difficult to say, which portion of an artwork comes from aesthetic principles, and which just follows the logic of the art. Aesthetics, logic and ethics come out as the different aspects of the same. This inner integrity makes what we call spirituality, and no art, science or philosophy is possible without an ideological load.
Of course, as we have three different categories interrelated in a fundamental way, there must be some reason, a common base and a general criterion of distinction. However, in the present context, we only stress the essential difference between art and aesthetics in their "direction": while art is explicating the universal content of everyday activities, aesthetics is concerned with adjusting everyday activities to the models suggested by art (and other types of analytical reflection). That is, instead of producing cultural phenomena, we are rather concerned with reproducing them on a higher level, as a concretization of an abstract idea. This subtle difference is not easy to trace in many practical cases. When an artist is to produce a generalized image of a class of activities, the choices are always backed by certain aesthetic principles, and it may seem that artistic creativity just implements a particular aesthetics. A closer consideration will indicate that an artwork is not a trivial illustration, containing some new elements that extend the original ideas; otherwise it just would not bear any artistic quality. Conversely, implementing an aesthetic principle may require a lot of creativity of all sorts, including a kind of art.
To distinguish aesthetics from other sides of synthetic reflection, like logic and ethics, we could just say that aesthetics implements the abstractions produced on the analytical level in a very specific manner, as an overall way of action, a general impression. This very different from what we do with logic, adjusting (possibly on the subconscious level) our activity to some explicit schemes, accepting a definite mode of action. The concretization of abstract ideas in the ethical line will result in a specific character of action, its cultural coloring, often regardless of the way and mode of action. Obviously, one does not need to restrict aesthetical concretization to mere art; scientific discoveries and philosophical views can also be implemented in an aesthetical manner, while artistic images may induce us into some logic or ethics.
Like any other aspect of activity, aesthetics can be reflected on the syncretic, analytical, or synthetic level. All the forms of synthetic reflection thus develop a rather complex hierarchy. Still, in a philosophical discourse, aesthetics becomes philosophy; in a scientific study, it grows into a separate science; artists express their aesthetic stand by illustrative action. All such projections onto the lower levels of the reflective hierarchy are equally important for the integrity of aesthetics as such. An artist (a scientist, a philosopher) needs aesthetics as well as logic or ethics. However, the immediate integrity of the aesthetic product (a representative activity) is akin to the manner of art to express itself in the form of other activities, and hence the close resemblance and inner kinship of the two levels of reflection. With all the due reserve, the mutuality of art and aesthetics is therefore perfectly justified.