Final answer:
Socrates suggests in 'The Republic' that the just city is an ideal to aim for as a conceptual model, not as a concrete reality. It serves to embody the principles of justice and virtue that should guide both individuals and societies, despite being unrealizable in a perfect form.
Step-by-step explanation:
At the end of Book IX of 'The Republic', Socrates suggests that the just city is an ideal to be strived for, even though it may never materially exist in reality. This ideal city serves as a model to understand justice and the virtues that should guide individual behavior. Essentially, Socrates believes that the just city, while idealistic, provides a valuable framework to envision what a just society would look like. However, this should not be misconstrued as Socrates claiming the just city already exists, nor that it is an irrelevant concept. His focus on philosophical inquiry leads to an understanding of justice that emphasizes the importance of governing oneself and one's society based on the principles of justice. Through the dialectical method, Socrates encourages continuous questioning and justification of beliefs, which is essential for the realization of a just individual and, by extension, a just society.