Plato’s Republic (330a) alludes to the story of Themistocles and the Seriphian, also found in Plutarch’s Lives. (Themistocles was the preeminent Athenian of his day, known for his accomplishments as a general and as a statesman. Serifos, a small island in the Aegean, was the Podunk of ancient Greece. Its main claim to fame was its mute frogs.) Anyway, one time Themistocles met a Seriphian “big fish” at a cocktail party or something, and their exchange went something like this:

SERIPHIAN: You may be a celebrity, Themistocles, but it’s hardly due to your own efforts — it’s largely an accident of birth. You would never have been famous, had you been born on Serifos.

THEMISTOCLES: Nor you, had you been born in Athens.

An anecdote with the same energy is told about Alexander the Great (whose great-great-great-grandfather Alexander I Philhellene briefly sheltered Themistocles when the latter was ostracized by his enemies). In this anecdote — mentioned in Longinus’ On the Sublime — Alexander’s army, under Parmenio, has just pushed back Darius III at the battle of Issus. Darius sends a proposal: Peace. Split the Persian Empire at the Euphrates. Darius to keep half, Alexander to take the other half.

PARMENIO: I should be satisfied with only one-half of Asia, were I Alexander.

ALEXANDER: Yes, and I should be satisfied with only one-half of Asia, were I Parmenio.

This story ups the paradox factor of the preceding, playing specifically on the ambiguity of what it means for Parmenio to be Alexander or vice versa. Remove the paradox, keep the energy, and you get the exchange often attributed to Lady Astor and Winston Churchill. Sometimes this exchange is described as the last two lines of a heated argument, but I prefer to imagine it sotto voce through smiles and gritted teeth in a receiving line:

LADY ASTOR: If you were my husband, sir, I’d put poison in your tea.

CHURCHILL: If you were my wife, madam, I’d drink it.