In Monumenti antichi inediti, Johann Joachim Winckelmann writes about ‘beauty’, stating that it cannot be defined: L’impossibilità di definire la bellezza nasce dall’esser ella una cosa superiore al nostro intelletto. Different dimensions and forms of the ‘negative’ indeed characterize the so-called ‘classicism’ and differentiate it from other genres of art (Realism, Mannerism, Gothic, Baroque, Romanticism, etc.): for example, the constitutive reference to ideas that cannot be expressed, a radical desubjectivation (both in the act of art production and in the experience of art), the necessity—but also the impossibility—of imitation in art, and the rather radical exclusion of feelings, visions, and personal experiences. This essay pursues two main objectives: (1) to highlight the elements of negativity that characterize the Kantian definition of the ‘aesthetic idea’ within the Critique of Judgment; (2) to situate Kant’s philosophy of the arts within the context of neoclassical reflection, to which it constitutively belongs. Against – or at least independently of – certain recent actualizations of Kant’s philosophy of art, we posit here the necessity of contextualizing it as accurately as possible.