Maybe I'm stupid, but does he mean that as long as the task at hand is solved it doesn't matter how we categorize it. In the submarine case it would be "move through water", for example. Or is it deeper than that?
No one knows the answer, it's an incredibly over discussed topic, and we won't know for sure for many years.
I think those points still apply to AI intelligence today. However, the power of today's AI greatly outstrips anything Djikstra would have seen in his day.
Yes