Julie Kelly is asking her girls if they can recommend a good mascara - one that won't clog up after it's been used twice. "Clinique's quite good," suggests Hannah, 18, a member of Julie Kelly's religious education A2 class. It's not an entirely flippant query.
These sixth-formers at Nottingham High School for Girls are discussing consumerism and, in particular, excessive consumption, questions of identity and a throwaway culture.
It's a subject close to Mrs Kelly's heart. This month sees the publication of a booklet on consumerism, part of a series of pamphlets on ethics produced by Christian publishing house Grove Books. It asks whether consumerism is now the chief rival to God in society, what that might mean for individuals, and what it might mean for the Church.
Mrs Kelly says she was prompted to suggest consumerism as a topic for the Grove series by her work teaching ethics as part of the A2 curriculum - she's a member of Grove's ethics group, which meets regularly to commission pamphlets giving a "broad Christian" response to current taxing issues.
Consumerism is part of the AQA A2 syllabus, followed at Nottingham High, where students are expected to consider it from a religious perspective (not necessarily Christian) and in terms of Aristotelian virtue ethics with its focus on character and achieving happiness as opposed to pleasure. The booklet is not intended as a teaching aid, Mrs Kelly says, but she had found earlier booklets useful in her lessons, and in 28 pages she provides a brief but thought-provoking tour of the arguments.
The book asks whether we now use consumerism as a way of constructing our identities - a new set of signifiers now that the old ones of class, geography, church and even profession are melting away. It darts from Andy Warhol to Madonna via Marx and King Solomon.
Along the way, it asks whether our mass consumption is at the expense of people who cannot afford to buy into the game, or who are exploited in the production of our cheap food and expensive trainers.
And whether it's at our expense too, as we try to cope with a world where the multitude of choice is simply making our lives more complicated, competitive and stressful instead of more comfortable.
RE and ethics are thriving at the independent Nottingham High School for Girls. Around a third of pupils take it at GCSE and almost 50 are studying it in the sixth-form. A weekly lunchtime discussion group is also popular.
(Today it's late abortions and infanticide. "We're doing pain and suffering next week, Miss," a girl shouts cheerfully on the stairs.) Mrs Kelly says she isn't surprised at the take-up, given the challenging and broad sweep of the subject - post-16 in particular. "It has become a very demanding subject. You have to get up to speed with the science. When we talk about arguments for the existence of God, we often end up discussing quantum theory, or the Big Bang. "There may have been elements of this in the past, but there are some really good syllabuses out there now. I'm not surprised people want to take RE."
If the ethics of shopping seems a natural subject for a group of well-to-do teenage girls, they're quick to engage with the complexities and contradictions involved.
"Fair trade is becoming really fashionable now," says Zi, 17. "I've got friends who are really into Coldplay (the pop group whose singer Chris Martin is a campaigner for the cause). They've given up shopping at some high-street stores and buying certain products. But are they just doing it because Chris Martin says they should?" Becky, 17, follows up: "Richer people like to say they can afford to buy organic. It separates them from other people who would if they could but can't." Even ethical consumerism is about separating yourself from the crowd.
Julie Kelly talks of the growing need for young people to be "ethically literate" in a world where complex and unexpected debates lie ahead.
"People will have some very important decisions to make. Science is moving very quickly and they will need to be ethically literate to know the terms of reference in these debates, know the questions to ask. We're trying to get them to see the whole board."
With that in mind, her sixth-form classroom offers girls a taste of what they might be expected to address as citizens and, indeed, as consumers.
The walls are plastered with newspaper headlines about cloning, globalisation, poverty and the environment.
She goes back to the issue of fair trade. "Some of the girls are quite concerned about that. But you can do something about that in the way you use your power as a consumer. It's not all negative. You can make good, wise decisions.
"I'm not for a minute saying I don't enjoy shopping. But I think it's important we think about what we're doing. In the end, money isn't inherently evil. It's the choices we make."
Consumerism pound;2.50, is part of Grove Books' Ethics series. To order, tel: 01223 464748 or www.grovebooks.co.uk