Daytime TV: Animal passions

Man is an animal of passion," declared Georgian brothel-keeper Jack Harris in City of Vice (More 4, Wednesday 15 April 10pm). Imbued with the 18th-century spirit of classification, Harris - although it was more probably one Samuel Derrick - compiled a list of London prostitutes, itemising their appearance, personality and speciality. "Good with mouth." That kind of thing.

Jack prided himself on catering for every kind of taste, and if some gentlemen went a little too far, well, that was just the way they were. "It's as natural as breathing," he remarked to Henry Fielding, whose Bow Street Runners were investigating a vicious attack on one Ann Bell, stabbed repeatedly in the "fundament" during intercourse.

This is the dark side of the Enlightenment. No rays of reason penetrate the smoke of the tavern or the steam of the bathhouse. Outdoors everything is the colour of dried blood. Man is cruel but at least he has conversation. Johnsonian cadences are everywhere, in the exchanges between Henry and his brother and in the curses of the man beating his dog to death in the street. Finely acted and atmospheric, it would depress even that fellow who said he could be a philosopher were it not for his cheerful disposition.

Pauline was definitely not cheerful. She had had an argument with her 81-year-old mother Josephine (Missing: Race Against Time, Channel 4, Thursday 16 April 9pm). We never did learn what it was about. But it must have been serious because Josephine disappeared with £10,000 in her handbag. "If someone tells her a sob story, she'll give them money," said another daughter. "She's a bugger like that." After three days Pauline decides to call the police. "To be quite honest," she tells a young constable, "I'd had enough of her." The grip on his pen tightened visibly.

But Pauline's tears told a different story. We were not dealing with a possible matricide, just messy family relations. "My mum's a very lonely lady," said another daughter. "She doesn't know what love is." Perhaps that's why she went missing, to look for it. Josephine was eventually found in an old people's home. "I was happy the second I walked out of that house," she said hoarsely. "Don't tell them where I am." Her daughters were relieved to hear she was safe and Pauline was probably thankful that mum wished to remain where she was.

Josephine was just one of the quarter of a million people who vanish each year. And most of them, to judge from this programme, appear to be working class. Really? The reasons why people go out in the morning and don't come back in the evening - financial worries, relationship problems, the need to be alone for a while - are not confined to any one section of the population. Or was the suggestion that those who live in council houses are less able to cope than those who live in their own homes? Television is less information than implication.

The facts themselves were almost banal. Of those who go missing, some are found, some are not. The first 72 hours are crucial. After that, the trail goes cold. As it long had for Vinny, who rang from an Indian restaurant to say goodnight to his son and was never seen again. As a documentary, Missing lacked bite, insight or purpose. But it made you think about getting yourself and your nearest and dearest tagged. Just in case.

It's not just people who go missing - so too does meaning, leaking out of our lives as we become ever more materialistic. Such is the contention of Michael Ward, author of Planet Narnia (The Narnia Code, BBC One, Thursday 16 April 10.35pm). Its basic thesis is that each of C.S. Lewis' seven Narnia novels corresponds to one of the seven planets. Various bespectacled faces and one bearded vicar were moved to ecstasy by the discovery, making you wonder what planet they were on. "Theism explains more than atheism" was one of many contributions that went unchallenged in this Christian love-in.

Michael explained that Lewis followed the medieval habit of giving a work different levels. The Narnia novels have three: the story, the Christian message and the planets. But medieval commentators stipulated four levels of meaning. So my advice to the bearded vicar is, don't get too carried away. Not yet.

Now, there are four children in the novels. They represent the medieval quadrivium. Together with the trivium, they made up the seven liberal arts. But there's no trivium in the stories. Lewis is telling us that the medieval world has gone. His other secret message is that we can win the lottery if we choose numbers that are multiples of three or four. Once you have a few million in the bank you won't worry about the meaning of life, just how safe your cash is going to be.