[spacechild1]

> Cultures that don’t practice infanticide are the exception in the historical and anthropological record

That's a non-argument. People did all kinds of horrible things in the past (human sacrifice, cruel corporal punishment, slavery) and yet it is now obvious to us that these things are bad. I think it is safe to say that infanticide is one of the things that we don't need to debate in modern times.

[barry-cotter]

You’re saying that it’s obvious infanticide is wrong. I’m pointing out that most humans ever have disagreed. Then you’re saying it’s obvious again and that it doesn’t need to be debated. Your “argument” is that the current moral fashions of your society are true and that this is obvious to all.

At best this is an attempt at persuasion by “Everyone else is doing it and so should you.”

[spacechild1]

Again, the same thing can be said about slavery.

In fact, if something is perceived as horrible by most people in current society, I think the burden is on you to explain why and when it is justified. (So far your only argument was that people in the old times did it, which is no argument at all.)

[barry-cotter]

Ok, so you’re assuming moral progress of some kind. Do you have any principled arguments for whatever it is you believe?