Immanuel Kant was acquainted with Baumgarten's work. In his Critique of Pure Reason (1781), Kant says that Baumgarten’s aesthetics can never contain objective rules, laws, or principles of natural or artistic beauty. Here’s an excerpt from Kant’s Critique: “The Germans are the only people who presently have come to use the word aesthetic[s] to designate what others call the critique of taste. They are doing so on the basis of a false hope conceived by that superb analyst Baumgarten. He hoped to bring our critical judging of the beautiful under rational principles, and to raise the rules for such judging to the level of a lawful science. That endeavor is futile.”
Kant conformed to Baumgarten's usage of the word “aesthetic” in his Critique of Judgment (1790). With his analysis of aesthetic experience, aesthetic creativity, freedom of imagination, and the connections between the aesthetic and the moral, Kant enriched the field of aesthetics. His work contributed to a rise in importance of aesthetics in the academic practice of philosophy.
Paul Guyer, in his essay, “The Origins of Modern Aesthetics,” (Chapter I, Visions of Beauty: Historical Essays in Aesthetics) conducts a review of developments in aesthetics in the 18th century. He holds that the figure of Kant is central to our understanding of aesthetics. Here’s a paragraph from Guyer’s essay in which he is explaining the significant contributions that Kant has made to the modern conception of aesthetics:
Kant’s complex and delicate interpretation of the freedom of the imagination in the experience of beauty can be seen as the summation and synthesis of ideas set forth at the outset of the flowering of modern aesthetics in the first decades of the eighteenth century. Kant transformed the idea of the autonomy of aesthetic response that Hutcheson derived from Shaftesury’s much more limited conception of the disinterestedness of judgements of taste into his basic conception of the free play of the imagination. At the same time, he developed Baumgarten’s conception of the complexity of aesthetic representation into an elaborate conception of the content of art and the symbolic significance of aesthetic response itself into a structure that could make room for Du Bos’s conception of the engagement of the emotions through the imagination and Addison’s idea of our love for images of liberty without sacrificing his guiding ideas of the free play of the imagination.