[tedsanders]

Good points. However, I don't think that "the ancients were fully aware" is an appeal to authority. I think the idea is ancient people tended to use things that were successful; therefore if the ancients used something, we should boost our confidence in it (relative to the baseline).

[pizza_boy]

You're partially correct. I'd say that we tend to adopt the successful cultural adaptations of our ancestors and discard the others.

In other words, when comparing an ancient society to one descended from it, I'd expect the "successful" adaptations of the ancestor culture to be disproportionately present in the descendant. The converse need not be true.

In Taleb's example Taleb of the builder, those ancient heuristics became our tort law (and will be a part of our reputation networks in the future). He doesn't mention all the cultural adaptations we've since dropped...

So it's obvious at best, and an appeal to authority at worst.