Here's my initial thought: "If pain is an evil, then inflicting it on others is immoral." That is probably very over-broad, because, for example, shooting a burglar or injuring someone trying to kill you would not be immoral. I think there are several texts we could cite in support of that.

I think we also have to be careful with the word "evil" in this and lots of contexts. Yes our feeling of pain is always undesirable, and from that point of view we consider it evil, but "evil" often implies much more - a religious or idealistic imperative never to do it under any circumstances. And there is no religious or idealist realm or function which establishes that, so that connotation of "evil" is not valid in Epicurean terms.

So issues with that part of the comment flow through to "But inflicting pain on others is questionable if it denies their option of accepting it for that later avoidance."

Depending on the context, we often probably are not concerned whether our infliction of pain on others, in our own defense at least, limits the other person's response options.

I'd argue that the same logic that applies in "On Anger" by Philodemus (see the SoFE site on this scroll) would apply here: pain can be both virtuous (if it produces long-term advantage / pleasure, for instance the ceasing of hostilities) and it can also be PRODUCTIVE.

Hiroshima, when the bomb exploded, was awful. But we have NEVER again had problems with Japan, which reformed itself as a country and is one of the most important global allies we have today. I can't say whether or not we may have gained a similar result through a different means, but in this case, hedonic calculus worked to produce security and long-term mutual benefit for both countries and the rest of the world.

It's always complex to debate specifics, and the Japan example is no exception. Was it needed? Was it appropriate? My answer on those questions has varied over the years, but it is difficult to dispute that it did bring the Japanese warmaking regime to an end more quickly than otherwise. Not taking a position on whether that was the right thing to do under the specific case, though. Probably easier is just the hypothetical normal homeowner being invaded with intent to murder by a random burglar, with the homeowner shooting the burglar or otherwise simply inflicting pain in order to protect his / her young children. I think most would agree that in virtually all such situations the infliction of pain was "correct."

Even those situations can be analyzed further, but what Epicurus was really saying I think is that there's no absolute standard by which we can look at a situation from outside and make an absolute judgment of right or wrong. The burglar apparently thought it would enhance his pleasure to invade the home. The homeowner thought it would advance his pleasure to stop him. Each side is making choices based on their view of their best interest, and both sides have to live with the consequences.

Even looking back at Japan vs USA, same analysis. Japan's leaders saw their interest one way, the USA's leaders saw it differently. One side one, and the other lost, but neither can legitimately claim that God or ideal virtue justified their side, because those things simply don't exist.

Absolutely. It would help so much to get to people much younger. I always remember that line from "ON ENDS" on that topic: “Was he, I say, to study arts like these, and neglect the master art, so difficult and correspondingly so fruitful, the art of living? No! Epicurus was not uneducated: the truly uneducated are those who ask us to go on studying til old age the subjects that we ought to be ashamed not to have learnt in boyhood!”

Possibly we ought to set up an "Epicurean Outreach" Forum, but for now probably this one: Special Challenges of the Modern World