The first ever English translation of Francois Hemsterhuis’ early series of philosophical letters published during the 1760s and 1770s. In this edition, the Letter on an Antique Gemstone, Letter on Sculpture, Letter on Desires and Letter on Man and his Relations are published chronologically to gradually reveal Hemsterhuis’ complete systematic vision. They are supplemented with three introductions: the first by Peter Sonderen pinpoints the significance of Hemsterhuis’ remarkably influential aesthetics; the second by Jacob van Sluis provides the context to his comprehensive Letter on Man and his Relations; and the third by Gabriel Trop focuses on the importance of these writings in the history of ideas, especially Herder’s translation and ‘Postscript’ to the Letter on Desires, Diderot’s commentary on the Letter on Man and his Relations and Goethe’s incorporation of Hemsterhuis’ definition of beauty into his aesthetic reflections.