[ben_w]

Mass murders aren’t the the thing that spills over into genocide — they get stopped when the shooter runs out of bullets etc. — it’s hate speech which spills over because it gets the speaker an army which can replenish itself.

To put it another way, it’s not like Hitler personally shot all the people he killed, he convinced other people to do it for him.

[brigandish]

Good, we're agreed, hate speech is vile. What we're not agreed on is the response. I am convinced by John Stuart Mill that I am not infallible therefore I should not be judge of who can and cannot speak. I can, however, judge the speech and think it is wrong and oppose it with my own speech. If they move to violence I may defend myself or others.

Or I could claim infallibility and judge that this is hate speech but that is not so this person cannot speak or say these things but that person can. In Germany, the person doing the judging was Hitler and people who agreed with him.

It doesn't sound like the best system to me. A big help to his plans was that the people denied the right to hold weaponry for personal defence were… Jews. As Frederick Douglass pointed out when talking about the oppression of blacks in America, without the right to bear arms the work of the abolitionists would not be over. History proved him (and Mill) right in Germany too.

[ben_w]

You say:

> A big help to his plans was that the people denied the right to hold weaponry for personal defence were… Jews.

Mill also said:

> That the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not sufficient warrant.

Which rather limits the effectiveness of — for example — the Jewish people taking up arms in self-defence in WW2. However, if you wish to argue that every victim of persecution was defending the other victims rather than themselves, the same argument would enable those same victims using their guns to shoot the propagandists. In fact, as Mill was a Utilitarian, I would expect [1] him to prefer that the free speech of literal-third-Reich-Nazis to be suppressed with a few literal bullets in the face, than to allow the holocaust to be escalated to 17 million dead.

[1] If someone resurrected him with an ancestor simulation, I’d expect him to have difficulty believing something that bad could happen and that it wasn’t merely a thought experiment like the utilitarian eyelashes thought experiment (whose formal name I’ve forgotten) or the trolley problem. However, as a note of caution to what I’ve written, although I’ve studied Philosophy formally, I got a poor grade and may be misrepresenting Mill without being aware of it.

[brigandish]

I think you've misunderstood the Mill quote. Immediately preceding the quote you used:

> the sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection.

He's saying that others cannot compel someone to do things, even if it is for their own good. They may only interfere for their own self protection. This implies and supports the right to self defence.

Ending the paragraph containing the quote you provided:

> In the part [of his conduct] which merely concerns him, his independence is, of right, absolute. Over himself, over his own body and mind, the individual is sovereign.

This does not in any way limit or argue against the effectiveness or right to self defence but instead, again, supports it. I'd encourage you to read On Liberty as, in my opinion, it is the greatest modern philosophical work.