Final answer:
Socrates considered justice to be an intrinsically valuable good and, together with Plato, theorized that justice is when every part of society fulfills its role harmoniously. Justice is closely linked to knowledge; knowing what is good leads to virtuous living and, hence, to happiness. Their dialogues in 'The Republic' explore the idea that an individual and society are just when each part operates according to its nature and purpose.
Step-by-step explanation:
When asking what kind of good is justice, we delve into the philosophical inquiries of Socrates, as represented in Plato's dialogues, particularly The Republic. Socrates viewed justice not merely as a tool wielded by the powerful, but as an intrinsically valuable good. He sought to understand whether 'good' was deemed so because the gods willed it, or if the gods willed it because it was inherently good, suggesting a standard of good independent from divine command. Socrates and Plato discussed how justice, virtue, truth, beauty, and knowledge are all facets of the good, united in their goodness.
In the conceptual just city in The Republic, Jo demonstrates that a society structured on mutual need and aptitude leads to collective happiness and success. This is essential for understanding Plato's theory of justice: justice is the specialization and harmonious functioning of all parts of society, each fulfilling its unique role, much like the harmonious movements of planets. To Socrates, the key to a virtuous life was the knowledge of the good; virtuous action stems from such knowledge, and evil arises from ignorance. Thus, for Socrates, to live justly is to live knowledgeably, which leads to the attainment of happiness.