Thomas frowned, wondering how it could be at once classified and in Sam's FBI dossier. He was about to say as much, but was pulled up short by a small flash of insight. 'Tell me, doctor,' he asked, 'did Neil ever mention the Argument?'

The bright eyes dropped to the table. For a moment he looked like something between a smiling Buddha and an Irish drunk.

'Oh, that.'

Thomas could feel Sam stiffen beside him. 'So he did talk about it,' she said.

'On occasion.'

'Would you mind relating the substance of those occasions?' she pressed.

'I'm afraid that's classified.'

Thomas frowned. 'Is it now?'

Mackenzie raised his small hands as though in surrender. His grin was contagious. His eyes fairly chirped with glee.

'Well it's should be.'

'And why's that, Dr Mackenzie?'

'Because it's true and because it's scary as all hell. What do you think secrets are for, Professor Bible?'

'In my experience,' Thomas said, 'truth is rarely as dangerous as people seem to think.'

'Ah,' Mackenzie beamed, 'so you're a cognitive psychologist.' Glancing at Sam's perplexed frown, he explained, 'Professor Bible doesn't think the Argument is dangerous because he doesn't believe the greater part of humanity is capable of believing it.'

'He's right,' Thomas said in response to Sam's questioning look. 'But not for the reasons you might think. It's not because people are too stupid—'

'Well,' Mackenzie interjected, 'not all of them, anyway.'

Thomas scowled and smirked. 'It's just that we suffer from so many biases. We like things to be simple. We have no stomach for uncertainty; just think of the way people throw snap judgments at their televisions. We're out-and-out addicted to praise. We cherry-pick evidence that confirms our beliefs and selectively ignore disconfirming evidence—'

'We rationalize,' Mackenzie interrupted once again, as though to simplify things for Sam's poor feminine brain. 'Why do you think science was so difficult for our ancestors to come by? It pretty much turns human psychology on its head, doesn't it, Professor Bible?'

You mean the soul, Thomas wanted to say. It turns our soul on its head. Instead he continued as though Mackenzie hadn't spoken—a petty punishment for his speaking out of turn. 'We do these things all the time—all of us. But the biggest thing, hands down, is that we confuse agreement with argumentative strength, or even worse, intelligence. Since we can only judge things in terms of our prior judgments, we make what we already believe the yardstick for what's right or wrong.'

Mackenzie chortled. 'Certainly explains the present political situation, wouldn't you say, agent?'

Of course the president was a Democrat.

Sam's face broke into an upside-down smile. 'I'm not sure I—'