There is one fundamental argument in the Republic for the conclusion that justice is the greatest good. It begins in Book II; although adumbrated in Book IV, it is not completed until Book IX; and it draws essentially on material in Books VI and VII about Platonic forms, knowledge, and philosophical training. Justice consists in the rule of reason over spirit and appetite, but to understand the value of this state fully we must see how it is instantiated in the philosopher. Goodness consists in order, and by cognizing and loving forms (the most orderly objects there are) the philosopher possesses the highest goods. A fully just person is a creator and lover of orderly relationships among human beings. This condition exists to some degree in all just individuals, but it is most fully present in those who understand what justice is – philosophers.