Immanuel Kant (1724-1804), German Enlightenment philosopher whose original and powerful philosophy has shaped most subsequent western thought. He was a popular lecturer, and was capable of a lively, readable style; although his major works are as dense and difficult as they are influential. (Kant defended this as a deliberate choice, since he wanted to examine what could be known about the mind in itself, or a priori, without depending on particular examples.)
Kant produced an early treatise on aesthetics, Observations on the Feeling of the Beautiful and Sublime (1763), and did not write on the subject again until the end of his career, in the Critique of Judgment (1790). In between the two works came the development of his influential critical philosophy. Although Kant saw the Critique of Judgment as the key work which connected his writings on epistemology (the theory of knowledge) in the Critique of Pure Reason with his writings on ethics in the Critique of Practical Reason, it is not necessary to know these other works in order to understand the most influential parts of Kant's aesthetics.
Like many other writers on aesthetics before him, Kant's main interest was not in art per se, but in Beauty (and along with other eighteenth century writers, in the Sublime). Thus most of his remarks are as relevant to the beautiful or sublime in nature as in art. Like other Enlightenment writers, (e.g, Hutcheson and Hume), Kant also thought that Beauty or Sublimity were not really properties of objects, but ways in which we respond to objects. (So they all wrote, not about the Form of the Beautiful, as Plato or a medieval philosopher would have done, but about Taste.) And like these other writers, Kant was concerned to show that this focus on the subjective aesthetic response did not make aesthetic value a mere function of individual or personal taste.
Kant's way of working out these problems is what makes his aesthetics original and influential. He claimed that judgments of taste are both subjective and universal. They are subjective, because they are responses of pleasure, and do not essentially involve any claims about the properties of the object itself. (What matters is not the picture I see; rather it is the pleasing effect of the picture on me.) On the other hand, aesthetic judgments are universal and not merely personal. That's because in a crucial way they must be disinterested. When I am appreciating a painting aesthetically, I am not thinking about how much money it's worth, or whether it is a portrait of a family member, or even about who painted it, except in so far as knowing the painter helps me see what's in the work. These non-aesthetic interests are extraneous to my appreciation of the painting. Rather I am pleased by the painting just for what it is, apart from anything I may get out of it. In fact I do not even take an ethical interest in the painting's subject (that is, any ethical interest is separate from this disinterested pleasure I take in the painting). "Taste that requires an added element of charm and emotion for its delight, not to speak of adopting this as the measure of its approval, has not emerged from barbarism" (CJ 13).
Kant thought that for aesthetic judgements to be both subjective and universal, they had to be about form. Beauty should be "a question merely of the form" (CJ 13). More specifically, the object being contemplated (e.g., a work of art, or an actual landscape) must display a kind of undefined purposiveness, such that it seems to be organized with a final purpose in mind, although it is not possible to say what that purpose is. Thus a work of art, or a beautiful natural object, displays a kind of free play of forms, consistent with the presence of a purpose to which we don't have access. So intent was Kant on emphasising the formal properties of the objects of aesthetic attention that he was unwilling to include color among the aesthetically relevant properties of an object. Color, in his view, is mere decoration; design and composition are what really matter (CJ 14).To sum up this point about form in Kant's own words: "A judgment of taste which is uninfluenced by charm or emotion (though these may be associated with the delight in the beautiful), and whose determining ground, therefore, is simply finality of form, is a pure judgment of taste."
Kant divided the kinds of aesthetic response into responses to the Beautiful and the Sublime. The one represents a pleasure in order, harmony, delicacy and the like. The other is a response of awe before the infinite or the overwhelming. While the beautiful presents the appearance of form, the sublime may often seem formless. The pleasure it gives us derives from our awareness that there is something in us that transcends the overwhelming power or infinity outside us.
Finally, Kant had things to say about genius. In short, he thought that genius has its own rules, and one cannot dictate to it.
How Kant arrived at his conclusions is not easily shown; and it is no surprise that the philosophical reasoning that grounds those conclusions did not follow them into the cultural mainstream. But the conclusions themselves proved quite influential. His remarks on genius, and on purposiveness in art and nature, had an impact on the development of Romantic aesthetics. Later, the idea of a disinterested appreciation of form became a watchword for philosophers and critics like Clement Greenberg who defended abstract art. In literary criticism, the New Criticism which focused on the text itself, and its philosophical defense by Beardsley and Wimsatt, were similarly inspired.