"A Citizen Of The World"

Context: Various persons have used this denomination of themselves, including Diogenes Laertius in Diogenes, 6 (c. A.D. 200), Thomas Paine in Rights of Man, Part II (1792), Chapter 5, and James Boswell in The Life of Samuel Johnson, LL.D. (1791), Everyman Edition, Vol. 1, p. 521. In this essay, Plutarch tries to console a friend who has been exiled from Sardis. The unhappiness caused by exile can be abated by wealth, friends, and freedom from politics. It is necessary to summon cheerfulness and peace of spirit from the good still left to us. Plutarch says:

For by nature there is no such thing as a native land, any more than there is by nature a house or farm or forge or surgery, as Ariston said; but in each case the thing becomes so, or rather is so named and called, with reference to the occupant and user. For man, as Plato says, is "no earthly" or immovable "plant," but a "celestial" one,–the head, like a root keeping the body erect,–inverted to point to heaven. Thus Heracles spoke well when he said
an Argive
Or Theban, for I boast no single city;
There is no fort in Greece but is my country;
whereas the saying of Socrates is still better, that he was no
Athenian or Greek but a citizen of the world.