# Book X explained — Dialogues > Chapter companion for Dialogues by Plato. ## What happens Socrates argues for the immortality of the soul, demonstrating that it cannot be destroyed by its own evils (injustice, intemperance, etc.) nor by external evils. He then describes the Myth of Er, a vision of the afterlife where souls choose their next lives based on their wisdom and virtue, emphasizing the supreme importance of philosophy and justice. Finally, he condemns imitative poetry for appealing to the lower, irrational part of the soul and undermining reason, and thus excludes it from the ideal state. ## Themes in this chapter ### The Soul and Immortality Socrates argues at length that the soul is immortal and imperishable, using the analogy of inherent evil and corruption to show that nothing external can destroy it. ### Justice and Injustice The entire discussion is framed around the choice between just and unjust lives, with the Myth of Er illustrating the eternal consequences of that choice. ### Education and Virtue Socrates emphasizes that only through philosophy and the cultivation of virtue can one make a wise choice of life, both now and in the afterlife. ## Character check-ins ### Socrates Leads the discussion on the soul's immortality, recounts the Myth of Er, and argues against imitative poetry. ### Glaucon Socrates' primary interlocutor; expresses astonishment at the claim of the soul's immortality and engages in the subsequent arguments. ## Key lines > And what will anyone be profited if under the influence of honour or money or power, aye, or under the excitement of poetry, he neglect justice and virtue? What benefit is there in pursuing honor, wealth, power, or poetic excitement if it leads one to abandon justice and virtue? _Socrates questions the value of worldly pursuits when they come at the cost of moral integrity._ > The vice and evil which is inherent in each is the destruction of each; and if this does not destroy them there is nothing else that will; for good certainly will not destroy them, nor again, that which is neither good nor evil. Each thing is destroyed by its own inherent evil; if that doesn't destroy it, nothing else can, since good or neutral things cannot cause destruction. _Socrates establishes the principle that only internal corruption can destroy a thing, setting up his argument for the soul's immortality._ > Let each one of us leave every other kind of knowledge and seek and follow one thing only, if peradventure he may be able to learn and may find someone who will make him able to learn and discern between good and evil, and so to choose always and everywhere the better life as he has opportunity. Each person should set aside all other pursuits and focus solely on learning to distinguish good from evil, so as to always choose the best life possible. _Socrates urges the supreme importance of moral wisdom in making life choices, as illustrated by the Myth of Er._ > The imitative poet who aims at being popular is not by nature made, nor is his art intended, to please or to affect the rational principle in the soul; but he will prefer the passionate and fitful temper, which is easily imitated. The poet who seeks popularity naturally appeals to the emotional, irrational part of the soul rather than the rational, because that is easier to imitate and more crowd-pleasing. _Socrates explains why imitative poetry is harmful: it strengthens the lower passions at the expense of reason._ ## Links - HTML: https://www.betterreads.online/discover/dialogues_se/chapters/book-x - Book: https://www.betterreads.online/discover/dialogues_se - All chapters: https://www.betterreads.online/discover/dialogues_se/chapters