This work explains and interprets Plato's dialogue Phaedo. Against the backdrop of the discussions on Eidos, psyche, and immortality and their interrelations, this study presents a precise commentary that supports a synchronous reading of the Phaedo. The interpretations of the dialogue's statements regarding the forms, the conception of the soul, and the doctrine of immortality are complemented by a comparison with the fundamental philosophical views on death and the afterlife from the pre-Socratics. In addition to a close textual examination of all arguments for immortality, the objections raised by Simmias and Kebes, and Socrates' refutations of these objections, this work also engages in a detailed explanation of the hypothesis method.