Ἀθάνατος

Philosophers assign the [word] "immortal" to animate things, but the [word] "imperishable" to inanimate ones.¹
"Plato, when maintaining that the soul is immortal,² assigns an equivocal term to immortal things. [This is] because what is strictly immortal is unchangeable, both according to substance and according to activity. However he knows that the soul is immortal according to substance but it is not also immortal according to activity. In this way you also might say that the heavenly bodies are homonymous with immortal things,³ for they also change, even though [they do not change] according to substance but according to place."⁴
"Immortality is a property of life and a kind of accident; for this is proved on the ground of a certain hypothesis that the immortal comes to be from the mortal, but the mortal comes to be immortal not because of participation in another life."⁵
[This] was written in the letter Pi, on affection.⁶
"But he who defines immortality as 'privation of mortality' makes a mistake. For immortality is not privation of mortality, but [resides] in a [sc. positive] condition and disposition."⁷