Eh, functioning is a very rough definition and we've got to that pretty quickly.

Yeah, but my point was that doing so is not actually useful because now we have to decide whether or not babies fit this criterion (and if this criterion is good), and we're inevitably going to do that by analogy and example if at all. I was trying to skip right to that step, but I suppose we did get there eventually.

If they do, then I can keep eating them happily enough; if they don't, I've got the dilemma as to whether to stop eating animals or start eating babies. [...] And it's not clear to me, without knowing what you mean by functioning, that pigs or cows are more intelligent than babies.

Pigs are smart. Pigs are very smart: they have complex personalities, developed rules of social interaction, intentional deception, object permanence, high ability to learn... given a few hours they can figure out how mirrors work and use them to see around or behind obstacles. The list goes on. (Even still, you would not be tempted to confuse them with people.) I'm pretty sure pigs are smarter than wolves, for example. Certainly, if you spend any time around them, pigs are "obviously" smarter than babies.

To my knowledge babies have none of those abilities, nor, indeed, many of the other characteristics of functioning people.

Regardless, I have no doubt that pigs are closer to functioning adult humans than babies are. You'd best give up pork. (Or do what I view as the reasonable thing and give up the idea that babies are people.)

I'd be interested in what standard of "functional" you might propose that newborns would meet, though. Perhaps give examples of things which seem close to to line, on either side? For example, do wolves seem to you like people? Should killing a wolf be considered a moral wrong on par with murder?

I have to ask, at this point: have you seriously considered the possibility that babies aren't people?

That depends on the nature of the script.

The script is as I described it. It's compiling an AI and then launching it. Here, I'll write it for you:

g++ SnazzyAI.cpp -o SnazzyAI && ./SnazzyAI

We are supposing that it's still on the first step, compilation. However, with no interaction on our part, it's going to finish compiling and begin running the sufficiently-advanced AI. Unless we interrupt it before compilation finishes, in which case it will not.

[...] when that happened infanticide became a sign of maladaptive behaviour. [...] People recognised a poor gambling strategy and wondered what was wrong with the person.

You seem to have gotten on something of a tangent here. I'm not sure why you're talking about maladaptive behaviors. I'm talking about immoral behaviors.

It is, for example, almost certainly maladaptive to allow all women to go into higher education and industry, because those correlate strongly with having fewer children and that causes serious problems. (Witness Japan circa now.) This is, as you put it, a poor gambling strategy. Does that imply it's immoral for society to allow women to be education? Do reasonable people look at people who support women's rights and wonder what's wrong with them? Of course not.

So no, maladaptive does not imply immoral. As such, I stand by my original point, which was that I don't think you would have invented a moral rule against infanticide if you weren't raised with one.