Next to no one actually thinks computers have literal intelligence (maybe kids, but even they treat such things as mere tools). They're regarded as basically a really complicated but useful abacus, not things capable of true thought. — MindForged

What do you think is the physical difference between a brain and a computer, that permits intelligence?

I think that Popper and Eccles really mean the sort of material determinism that takes the universe from one state to the next. If you admit the causal power of "animals" and "design" you are already stepping outside material determinism, into a situation where abstractions are causal. I think the two conceptions are distinct, and this could be the cause of some confusion.

"Rationality and determinism are incompatible. Why? Because you require free will in order to be rational. Why? Because if you lack free will, all you choices a determined i.e. determinism is true."

It appears that the conclusion is inserted into the premises of the argument. — Chany

A computer can be programmed to make rational decisions without giving it the property of free will, so I'm not convinced the conclusion is in the premises. Then it seems to boil down to whether it is the rationality encoded in the software or the atoms in the hardware that are causing the decision.

There seems to be different conceptions of determinism at play: one based on the closure of physics, the other seems to admit other forces such as reason. I don't understand the latter conception.