A computer CPU executes a very large number of mathematical calculations - or rather, a simulation of mathematical calculations - in binary code. No matter how powerful the CPU, or no matter how many CPUs are linked together, the computer or computer always remains at the level of simulated mathematics. It cannot rise one milllimetre towards true thinking.

True thinking means grasping abstract concepts. We examine a number of diverse objects and extract from them something non-material (and non-mathematical) that they have in common. So after looking at a collection of green living things, we abstract the concept of 'tree'. These things that physically may look quite dissimilar all have something in common - a nature, itself not reductible to physical phenomena. They are trees.

With the exception of names and proper nouns (and not even them really), every word in English expresses an abstract concept, something that itself is not physical but is possessed in common by physical entities. Abstract concepts extend to every part of our understanding of the universe: 'beautiful, 'good', 'evil', 'useful', 'expendable', and so on. A computer does not begin to comprehend them. It just performs mechanical simulations of mathematical calculations. It doesn't even understand the maths it does. We understand the truth behind the affirmation that 2 + 2 = 4. A computer is just programmed to produce a mechanical simulation of that calculation.

Since computers can't think they can't make decisions based on thinking. They can't, for example, conclude that the human race is a blot on creation and decide to exterminate it. They can't actually make decisions at all. They have no free will. Their 'decisions' are simply the end result of preprogrammed calculations. If they get things wrong, blame the humans that programmed them. They're just tools really.

(I copied this post from another thread as it seems interesting enough to have a thread of its own)