Last night's viewing - Sex, Death and the Meaning of Life, More4

Richard Chell, dying of motor neurone disease, thinks that not believing in life after death is like only having "half a meal", it leaves the human appetite dissatisfied. Richard Dawkins, dying of life in general (like all of us), thinks that appetite doesn't have anything to do with it: "The existence of hunger doesn't mean there's food," he countered last night in Sex, Death and the Meaning of Life.

But Dawkins is interested both in the hunger and what might appease it in a world without God: "How does someone like me who has no religion face death?" he asked, at the beginning of the second of his examinations of how life might be lived without faith to underpin it.

I wouldn't recommend his first step to the faint-hearted. He went off to Varanasi in India, where devout Hindus depart this world with a bracing lack of squeamishness. Nobody very much seemed to mind that a wild dog was treating one of the funeral pyres as an impromptu barbecue or that the water in which they were conducting their devotions also contained a bloated corpse. I wouldn't advise his second step either, which was to visit a Kansas hospice for babies bound to die within hours of birth. And curiously it wasn't easy to fit either of these scenes directly into Dawkins' argumentative ambition. "Reality may be raw," he said in Kansas, "but we have to face it." But all the evidence, of thousands of years of human culture and these two sequences as well, is that we don't have to, at least not face-on.

I'm with Dawkins in believing we should, but it's not hard to see why people find the alternative attractive. A young couple in Kansas talked with great serenity about the recent death of their baby, born without kidneys, and were utterly convinced that they would one day be reunited. "They sincerely think they're gaining reassurance from their faith," concluded Dawkins sympathetically. But the flat truth was that they were reassured. They might be entirely wrong about what happens next, but since they're not going to be in a position to kick themselves for their credulity, it's hard to argue that they've lost out.

Dawkins also has a way of conflating "sentiment" with "illogic", which sometimes feels as if it's missing the point, because sentiment isn't dismayed by accusations of irrationality. It takes pride in it. That's partly what sentiment is for – to fill the gaps in our rational understanding that would otherwise let a chill wind blow around us. Again, I'm with Dawkins in preferring the breeze to the insulation, but I'm not optimistic about the prospects of getting everyone to give it up. You could argue (Dawkins almost certainly would) that evolution has just done too good a job in embedding such consolations within us.

He's certainly up to the task of offering an alternative, though. The second half of this thoughtful film concentrated on a scientific account of why we might have such a strong intuition that there is something in us besides physical matter and an exploration of genetic immortality. Dawkins had his own genome mapped (revealing, incidentally, that he's prone to runny earwax and can smell asparagus in his pee the day after eating it) and ended standing by the Dawkins family tomb in an English church, the inscription on the wall listing the ancestors who had contributed to his own unique collection of genes. He would like, he confessed, for the hard drive containing his own gene code to lie alongside his familial predecessors. A slightly illogical impulse that, but a reminder that we do get a kind of immortality in what we pass on to our children and they pass on to theirs. "I" might not be around to be aware of it – as in more well-established forms of afterlife – but it's enough for me.