ABSTRACT
Books 8 and 9 round out that overarching argument that began in Book 2 with the two goals of defining justice and showing its profitability. It might appear that by the end of Book 4, in which he described justice as a harmony akin to health (444d–e), Socrates had achieved both aims. But Glaucon wanted Socrates to demonstrate, not merely that justice in the soul is worth possessing – not merely that it is profitable – but that one would rather possess justice in the soul than any other psychological arrangement: that justice is the most profitable of all conditions, that the just soul is the happiest of all possible souls (⑧). So Book 8 begins with the announced aim of contrasting justice with every form of injustice, in order to show that each of these will generate less happiness than justice does, both in the person and in the city. Whether the Republic aims at showing that a just person will be happy no matter what the circumstances (as Plato’s ancient readers believed), or (as today’s readers mostly say) only argues that in any given circumstance the just are happier than the unjust: either way, justice must emerge victorious in the coming comparison.
