In the Phaedo – a dialogue investigating the immortality of the soul – Socrates compares himself to the swans of Apollo who sing “most beautifully” before they die. Working principally from the Phaedo, the aim of this article is to determine the relation between the song of the swan and the song of the philosopher. First, we examine the use of language in human song as a way to consider the other side of logos: logos not only as word but logos as ratio – i.e., as a relation between temporally-ordered terms. This ratio we then examine as the sense of before-and-afterness that Aristotle explores, in Physics IV, as the “number of movement” that is time; for, through the counting of this “number of movement”, we begin to understand how swans and philosophers share a temporal orientation toward what transcends the present moment. This temporal orientation, I argue, pertains to sempiternity, an ageless or undying [ἀθάνατος] movement of the soul. Thus, I conclude that philosophy as “the highest kind of music” – like the song of the swans of Apollo – concerns itself with the undying state of the soul and, hence, with ethos.