Although thinkers and sages have pondered beauty and art for thousands of years, the subject of Aesthetics wasn’t set apart as an independent philosophical discipline until the 18th Century by German philosophers. Before this period authors viewed the study as inseparable from other main topics, such as ethics in the Western tradition and religion in the Eastern tradition.

Ancient Greece
Greek philosophers initially felt that aesthetically appealing objects were beautiful in and of themselves. Plato felt that beautiful objects incorporated proportion, harmony, and unity among their parts. Similarly in the "Metaphysics" Aristotle found that the universal elements of beauty were order, symmetry, and definiteness.

18th and 19th Century Europe
In 1750, Baumgarten published the book "Aesthetica" in which he took the term encompass a science of sensual recognition. Baumgarten tried to create a place for this new "lower" science of aesthetics with the "higher" science of logic, so that a discussion of the beautiful would not be reduced to a mere discussion of taste ("Geschmack").

In his 1790 book "Critique of Judgment," Immanuel Kant called Aesthetics "the science which treats of the conditions of sensuous perception". Kant emphasized beauty, taste, transcendence, and the sublime. Beautiful art might fall into the category of what we think of today as pretty, pleasant, or pleasing to the eye. Sublime images on the other hand were awe-inspiring. Dramatic scenes from nature such as vast mountainscapes, the dazzling sea, or light shining through forested trees might produce an experience of the sublime. The Irish philosopher Edmund Burke also made an important contribution an the question of the sublime and beautiful. Kant insisted that aesthetic judgment is always singular, of the form "This rose is beautiful." He denied that we can reach a valid universal aesthetic judgment of the form "All objects possessing such and such qualities are beautiful."

The German Georg Friedrich Wilhelm Hegel and later French philosophers J. Cousin and Jean Charles Leveque developed an elaborate system of aesthetics regarding it as spiritual in nature. The several beautiful characteristics of an organic body (the principal ones of magnitude, unity and variety of parts, intensity of color, grace or flexibility, and correspondence to the environment) may be brought under the ideal grandeur and order of the species. These are perceived by reason to be the manifestations of an invisible vital force. Similarly the beauties of inorganic nature were to be viewed as the grand and orderly displays of an immaterial physical force. Thus all beauty was in its objective essence either spirit or unconscious force acting with fullness and in order.

Modern Philosophy
The field of aesthetics has enjoyed a rebirth in recent years. Post-WWII Modern art -- particularly up through the 1980s -- strongly reacted against notions of beauty. Some theorists (Hal Foster) have described this as an "anti-aesthetic." Since artistic media were deconstructed and explored to their very foundational or essential elements, creating an aesthetically beautiful work was no longer the key. Instead, artists focused on conceptual questions such as 'what is art?' or 'who defines art?' For instance, the artist Joseph Beuys used materials such as heavy dark felt, dirt, logs, bones and sticks, all of which might be considered to be quite "ugly" by traditional understandings of beauty and aesthetics.

Art today might be said to be more embracing, or at least better engaged with current notions of the beautiful or sublime. Theorists such as Jeremy Gilbert-Rolfe have discussed how the intensification of capitalism and new technologies might be developing a new notion of sublimity. Visual culture theorist Johanna Drucker proposed that contemporary artists recognize their complicity with the dominant ideologies of beauty and aesthetics, and may both critique and embrace these aesthetics simultaneously.