The four men are sitting around a table, filled with wine and grapes– and they appear to be engaged in a civilized discussion. The four men on the drawing are the brothers Wilhelm and Alexander von Humboldt, respectively statesman and explorer, the poet Friedrich von Schiller and, of course, scientist, writer and poet, Johan Wolfgang von Goethe.
The four of them were the intellectual fab four of late 18th century Germany. They strongly believed in the powers of reason – as opposed to royal decrees or religious dogmas. They strongly believed that individuals were to be enlightened – through science, art, and literature. They strongly believed in "sapere aude" – in daring to know.