It is well known to readers of the Republic that, according to Plato's representation, a casual meeting of several friends develops into a sederunt for the express purpose of finding a solution to the question, what is justice? The question has its origin in the remark of the aged Cephalus, quoting Pindar, that whoever lives a life of justice and holiness,

Sweet hope, the nourisher of age, his heart

Delighting, with him lives; which most of all

Governs the many veering thoughts of man.