More little green men
Going back to extraterrestrials.
I seem to remember reading about a theory created by someone very clever. Possibly an astronomer. The theory was that if an alien civilisation reached the stage of achieving interstellar (or possibly intergalactic) travel, it must be benign and peaceful. Partly because those kinds of activities require peaceful cooperation, and partly because civilisations that weren’t peaceful would have destroyed themselves before they reached this stage. Presumably because nuclear weapons are easier to develop than interstellar transport, and therefore likely to be developed first. (Or the possibility of nuclear weapons is likely to be discovered, even if they aren’t developed).
This seems pretty convincing to me as far as it goes, but I don’t see why it would be impossible for a warlike, or potentially warlike, civilisation to start hopping between solar systems. For example, the civilisation could be accustomed to preying on weaker counterparts, but have internal stability due to strong, rigid power structures. What it boils down to is that making guesses about the nature of alien civisations, if there are any, can be a tricky business.
Given the problems that the earth’s biosphere has at the moment, maybe there is a case for saying that, if alien civilisations more advanced than our own are likely to be benign and friendly, we should be doing everything we can to attract their attention, in the hope that they’ll come along and help us out of our problems. The flip side of this, I suppose, is what would happen if we caught the attention of hostile or imperialistic aliens?
I don’t have the answer to these questions, but I think they’re important enough that it’s OK for both clever people and not-so-clever people to be thinking about them. Because the universe is a big place, and the multiverse is even bigger. Even if humans are the only intelligent ‘species’ that exists, thinking and talking about these kinds of issues can help us to appreciate more clearly our place in the great scheme of things.