One should neither hesitate to engage in philosophical activities in youth nor perceive philosophy as a burden in old age. Epicurus. The Letter to Menoikeus is the central text for the ethics of the Greek philosopher Epicurus and the only one fully preserved in this area of his teachings. The significance of the text arises not only from its state of preservation but also from its content, as it succinctly and clearly encompasses nearly all the fundamental guidelines that Epicurus deemed essential for a life of happiness. This work presents the first critical edition of the letter in 40 years, a new translation, and a comprehensive scholarly introduction to general aspects of Epicurean literature and specific issues of the letter: it explains the intention, the literary and linguistic form, as well as the themes of the letter.