Maybe humans are what happens high intelligence evolves in an animal that also has hands, and dolphins are what happens when comparably—if not still more extravagant—intelligence evolve in an animal without hands.
Hands basically get you an appetite for punching people in the head. It makes us tool users, but the distance between the hammer you use to knock open your coconut and the hammer you use to knock open the head of the other CroMagnon you’re not too keen on is zilch. There’s no difference at all.
I’d all but forgotten about John Lilly’s dolphin experiments, but what struck me here was the intimate relationship between tools and weapons. It’s quite obvious when you think about it, but it’s not something I’ve thought about much before. My son’s dual obsession with both tools and weapons makes a bit more sense now (and is a bit more scary).