The article delves into the theme of the sublime in Schiller’s philosophical works, examining its relationship with the esthetical and educational framework outlined in the Letters on the Aesthetic Education of Man. In his famous 1795 essay, Schiller’s predominant focus on the beautiful, almost to the exclusion of the sublime, historically led to interpreting the latter as detached from Schiller’s theoretical core on beauty and esthetic education. This study proposes a dialectical and synthetic perspective on the relationship between beauty and the sublime, contributing to a unified view of Schiller’s reflection on esthetic education. First, the article analyzes the role of sensible affects in the transition from Kantian esthetics of the sublime to Schiller’s theory of the tragic. In this metamorphosis, Schiller develops a new notion of imagination, shifting from the Kantian transcendental structure into a faculty of mediation between the sensible and the rational, which will become the cornerstone of the whole experience of beauty in the Aesthetic Education. The analysis concludes by examining Concerning the Sublime, supporting the hypothesis of later dating and considering it as a continuation of the incomplete Aesthetic Education essay. This writing embodies the unity between beauty and the sublime within a single educational project, grounded on the role of imagination in estheticizing the sensible world.