Will Machines Ever Become Human?
No. Digital computers won’t; and in the world as we know it, they are the only candidate machines.
What does “human” mean? Humans are conscious and intelligent—although it’s curiously easy to imagine one attribute without the other. An intelligent but unconscious being is a “zombie” in science fiction—and to philosophers and technologists too. We can also imagine a conscious non-intelligence. It would experience its environment as a flow of unidentified, meaningless sensations engendering no mental activity beyond mere passive awareness.
Some day, digital computers will almost certainly be intelligent. But they will never be conscious. One day we are likely to face a world full of real zombies and the moral and philosophical problems they pose. I’ll return to these hard questions.
The possibility of intelligent computers has obsessed mankind since Alan Turing first raised it formally in 1950. Turing was vague about consciousness, which he thought unnecessary to machine intelligence. Many others have been vague since. But artificial consciousness is surely as fascinating as artificial intelligence.
Digital computers won’t ever be conscious; they are made of the wrong stuff (as the philosopher John Searle first argued in 1980). A scientist, Searle noted, naturally assumes that consciousness results from the chemical and physical structure of humans and animals—as photosynthesis results from the chemistry of plants. (We assume that animals have a sort of intelligence, a sort of consciousness, to the extent they seem human-like.) You can’t program your laptop to transform carbon dioxide into sugar; computers are made of the wrong stuff for photosynthesis—and for consciousness too.
No serious thinker argues that computers today are conscious. Suppose you tell one computer and one man to imagine a rose and then describe it. You might get two similar descriptions, and be unable to tell which is which. But behind these similar statements, a crucial difference. The man can see and sense an imaginary rose in his mind. The computer can put on a good performance, can describe an imaginary rose in detail—but can’t actually see or sense anything. It has no internal mental world; no consciousness; only a blank.
Bur some thinkers reject the wrong-stuff argument and believe that, once computers and software grow powerful and sophisticated enough, they will be conscious as well as intelligent.