Aristotle never wrote the phrase the golden mean. His term is mesotēs — plainly, the mean — with no gold anywhere near it. The gold arrives three centuries later, in Latin, from Horace: auream quisquis mediocritatem diligit, whoever loves the golden mean, in a poem about not sailing too far out and not hugging a dangerous shore. English welded the two together and credited the wrong man.

There's a small irony in the Latin. The word Horace is praising — mediocritas — is the direct ancestor of English mediocrity. He meant the middling state as an achievement. Two thousand years later it's an insult.

But the substantive corrections matter more. First: the mean is not an average. Aristotle says it's determined relative to us — it depends on who is acting and what they are facing. No fixed quantity of food is right for every athlete, and no fixed quantity of anything else is right for every person. Courage is a mean, and the right amount of courage for a soldier under fire is not half-bravery. Which is also why finding it requires phronesis rather than arithmetic.

Second, and more decisive: some things have no mean. Aristotle names them outright. Envy, spite and shamelessness among the feelings; theft, adultery and murder among the deeds. These are not quantities to get right — there is no circumstance that makes them correct. They fall outside the doctrine entirely.

So moderation in all things is not the teaching. There is no correct amount of murder.