Anarchism is a fantasy of fools.
Perhaps, but as a wise man once observed:
Anarchy is just freedom you don't like; Freedom is just anarchy you are in favour of.
So we can conclude that freedom is also a fantasy of fools.
But the absence of absolute freedom does not imply that authoritarianism is not real, or is not a bad thing.
Correct. Authoritarianism is real and is a bad thing. But that plus you misdefining authoritarianism is not even remotely sufficient to show Emily's desire to have a legal rule is "authoritarian" and therefore a bad thing. You very much have burden-of-proof on that.
We need just enough law to protect ourselves from tyrants, and no more.
That's patently ridiculous. I hope I don't offend your sensibilities too much by returning to the 13th century, but back then a popular public entertainment was catching cats and setting them on fire. Thankfully we now have laws against that sort of monstrosity. It's painfully obvious that we do not need laws against cruelty to animals in order to protect
ourselves from tyrants -- we need them to protect
animals from tyrants. This is not rocket science.
My claim, which you are apparently attempting to dispute, was:
If you desire to limit freedom by the passing of laws then you are an authoritarian. That's what the word means.
(bold added).
If you desire to protect freedom by the passing of laws, then I wasn't talking about you. But that's not what
@Emily Lake was advocating.
There are two things wrong with that line of argument. First, no, that's not what the word means.
"Authoritarianism is a political system characterized by the rejection of political plurality, the use of strong central power to preserve the political status quo, and reductions in democracy, separation of powers, civil liberties, and the rule of law."
en.wikipedia.org
So Emily could outlaw goatees and it wouldn't qualify as authoritarianism as long as it was democratically enacted and the pro-goatee faction are allowed to make their case to the public and field opposition candidates in free elections.