‘So does the computer. Or at any rate, it would take a damned complicated computer to say the words without meaning them. I mean, what do we mean by “mean”? If we want to know whether a man or a computer means “O Lord, bless the Queen and her Ministers,” we look to see whether it’s grinning insincerely or ironically as it says the words. We try to find out whether it belongs to the Communist Party. We observe whether it simultaneously passes notes about lunch or fornication. If it passes all the tests of this sort, what other tests are there for telling if it means what it says? All the computers in my department, at any rate, would pray with great sincerity and single-mindedness. They’re devout wee things, computers.’

‘Y-e-e-e-s. But I take it you don’t believe in a God who hears and answers prayers?’

‘That’s not my end of the business. I’m just concerned with getting the praying done with maximum efficiency and minimum labour output.’

‘But, Macintosh, if you’re as cynical as that, what do you think the difference between man and computer is?’

‘I’m not absolutely certain, Rowe. I’m inclined to rule out what you might call “soul.” I should think that in time we could teach computer to be overwhelmed by the sound of Bach or the sight of another computer, to distinguish between good sonnets and bad, and to utter uplifting sentiments at the sight of the Matterhorn or the sunset. Obviously it’s not the faculty of choice; computer can be programmed to choose, just as man does, rationally, anti-rationally, at random, or by any combination of the three. Some people, of course, have set a certain store by the human capacity for faith. But I don’t think it helps us much here. If you tell computer that the sky is green, computer will believe you. Or you could programme computer to perceive empirically that the sky is blue, but to act on a profound, unspoken faith that it is green. Think of that, Rowe! And if you objected that this faith was forced on him willy-nilly, then you might imagine a computer programmed to choose whether to believe the evidence of his senses that the sky is blue, or whether in spite of what he saw to accept that it was green because its operator had told him it was.’

‘I suppose so,’ said Rowe.

‘Now you and I, Rowe, as practical men, would say that the only useful working distinction between man and computer is that computer can choose only from among a finite range of variables, whereas man can specify for himself the range of variables from which he will choose. But it’s a wee bit tenuous, because it depends simply on the complexity of man’s neuro-mechanism. I suppose one day we shall build a computer as complex, and it will begin to specify its own limitations.’