A classic of 18th-century thought, Schiller's treatise on the role of art in society ranks among German philosophy's most profound works. An important contribution to the history of ideas, it employs a political analysis of contemporary society — and of the French Revolution, in particular — to define the relationship between beauty and art. Unabridged republication of the Reginald Snell translation as published by Yale University Press, New Haven, 1954.
Here's a sample of other books in this Dover category
On Education by Immanuel Kant Rather than a systematic study of theories, the famous philosopher offers a succinct treatise of his thoughts on education, including a proposal for raising the science of education to academic status.
Laocoon: An Essay upon the Limits of Painting and Poetry by Gotthold Ephraim Lessing, Ellen Frothingham In this essay on the origins, forms, and influences of painting and poetry, Lessing helped frame modern conceptions of the artistic medium, and founded our modernist assumptions of the uniqueness of the individual arts.