The paper is the presentation (as the transcription and translation of the text) of the letter written by the humanist and classical scholar, Iustus Lipsius (1547-1606), and entitled by its editor in Cracow Epistola erudita (1602). The rhetorical analyses of this text is based on the Lipsius's treatise Epistolica institutio (The Principles of Letter-Writing). The main problem concerns the role of traditional rhetoric in the letter writing, especially if the letter is not reduced to a formal document, prepared using repeatable formulas. Early modern epistolography (Petrarca, Erasmus, Lipsius, Vives) recovers the ancient tradition of letter writing, according to which the letter is a kind of written conversation. It gives unique opportunity to meet each other in the symbolic universe of the text.