It could <i>always</i> all be unreal - how could you ever tell otherwise? You took it on trust, in part because what would be the point of doing anyt… - Iain Banks

The point is: what happens in heaven?'

'Unknowable wonderfulness?'

'Nonsense. The answer is nothing. Nothing can happen because if something happens, in fact if something can happen, then it doesn't represent eternity. Our lives are about development, mutation and the possibility of change; that is almost a definition of what life is: change.'

'If you disable change, if you effectively stop time, if you prevent the possibility of the alteration of an individual's circumstances - and that must include at least the possibility that they alter for the worse - then you don't have life after death; you just have death.

I think I know the real reason."
"Which is?"
"Alcohol in the dust clouds. Goddamn stuff is everywhere. Any lousy species ever invents the telescope and the spectroscope and starts looking in between the stars, what do they find?" He knocked the glass on the table. "Loads of stuff, but much of it alcohol." He drank from the glass. "Humanoids are the galaxy's way of trying to get rid of all that alcohol.

Any theory which causes solipsism to seem just as likely an explanation for the phenomena it seeks to describe ought to be held in the utmost suspicion.