Why did Immanuel Kant think aesthetic enjoyment should be separated from practical use?

Immanuel Kant argued that aesthetic enjoyment must be separated from practical use because he defined the aesthetic experience as being disinterested.1

For Kant, to contemplate an object aesthetically means to view it "apart from all interest," meaning the recipient does not treat the object as a vehicle for curiosity, a means to an end, or a tool for practical utility. When an object is viewed through the lens of its purpose or use, the observer is no longer engaged in pure aesthetic contemplation but is instead focused on conceptual or instrumental concerns.1

This "disinterested" state is essential to Kant’s philosophy because it allows for a "free play" between the imagination and the understanding. By setting aside personal interests and practical urgencies, the observer can appreciate the object for its own sake, which Kant identified as the foundation of a true judgment of beauty. This detachment ensures that the pleasure derived from the object is immediate and not based on any external desire or conceptual goal, thereby distinguishing aesthetic judgment from scientific or practical reasoning.2314