It seems that the paper discusses the inside view of intelligence, not the ways to detect one by its non-human-like artifacts.
I agree that it is hard to tell an intelligence without pattern-matching it to humans, that’s why I asked the question in the first place. But there hopefully should be at least some way to be convinced that a rock is not very intelligent, even if you can’t put yourself in its crystalline shoes.
It seems that the paper discusses the inside view of intelligence, not the ways to detect one by its non-human-like artifacts.
I agree that it is hard to tell an intelligence without pattern-matching it to humans, that’s why I asked the question in the first place. But there hopefully should be at least some way to be convinced that a rock is not very intelligent, even if you can’t put yourself in its crystalline shoes.