That's a rather interesting line to me, as someone with a young child, they cannot perform that abstract reasoning on mathematics either. At the same time, I fe

That's a rather interesting line to me, as someone with a young child, they cannot perform that abstract reasoning on mathematics either. At the same time, I feel extremely confident they're a thinking and intelligent being. I think we're so strongly biased against a deeply uncomfortable reality that there may not be a hard line, we don't even want to consider the alternative.