It should be noted that the Stoic theory of oikeiosis is a theory of what "belong to us" and that in Plato's Republic (around 434a) Socrates defined justice as "doing what is one's own - what naturally belongs to us". Plato's theory of justice is a theory of oikeiosis just as the Stoic theory of oikeiosis is also a theory of justice.
It should be noted that the Stoic theory of oikeiosis is a theory of what "belong to us" and that in Plato's Republic (around 434a) Socrates defined justice as "doing what is one's own - what naturally belongs to us". Plato's theory of justice is a theory of oikeiosis just as the Stoic theory of oikeiosis is also a theory of justice.