Argument for Immortality of Soul at Phaedo 78b-80d

1. Things that vary are likely to be composite (78c)

2. Composite things are likely to be broken up and scattered (78b-c)

3. The body (being composite) is subject to change. (78e-79a)

4. The body is also visible.

5. Forms are known only by the mind (by the soul by itself) (79a)

6. The forms are intelligible, not visible.

7. Whatever remains in the same state is likely to be noncomposite. (78c)

8. The Forms remain in the same state. (78d)

9. The Forms are unchanging, i.e., eternal.

10. The soul is not visible, but intelligible. (79b)

11. The soul, when by itself (not distracted by the body), is unchanging. (79d)

12. The soul is more like the Forms than it is like the body.

13. The body is naturally ruled while the soul naturally rules it. (80a)

14. The gods are natural rulers, while mortals are naturally ruled by them. (80a)

15. The gods are deathless.

16. [Compared to the body] the soul, considered by itself, is most like the divine, deathless, intelligible, uniform, indissoluable, always the same as itself, while the body is most like that which is mortal, multiform, unintelligible, subject to dissolution, never consistently the same. (Intermediate conclusion, 80b)

17. The soul will not be scattered and destroyed upon leaving the body. (Final conclusion, 80d, implicit in rhetorical question)