Full Idea
It is not correct to claim that guardians are to be harsh to those they do not know, since one should not treat anyone in this way.
Gist of Idea
The guardians should not be harsh to strangers, as no one should behave like that
Source
Aristotle (Politics [c.332 BCE], 1328a07)
Book Reference
Aristotle: 'Politics', ed/tr. Reeve,C.D.C. [Hackett 2017], p.168
A Reaction
This seems to be a criticism of Plato. Aristotle thinks people should be nice to one another! The ancient tradition of hospitality to strangers.