The big questions are being asked by pupils at Mearns Primary. "Why are there so many religions?" "Why do we have to recycle?" And "why do old people love gardening?"
These searching queries are overheard during the school's respect day, when policemen, religious figures, older people and mental health workers, among others, discuss weighty issues with P7 pupils for 90 minutes.
The session was central to the annual event at the Newton Mearns school, which builds on an idea local police superintendent Stewart Daniels had in 2004 as he pondered why youngsters often seemed to lack respect for authority. It has led to several East Renfrew-shire schools organising respect days.
Superintendent Daniels is one of the most popular visitors at Mearns where, in a large hall, groups of about eight pupils speak with him in a circle for a few minutes before moving on to another visitor. He brings policing paraphernalia to grab pupils' attention, such as the Taser, a weapon that administers an incapacitating electric shock.
He steers discussion away from a fascination with its physical effects, asking the children how to negotiate and avoid using the Taser.
Superintendent Daniels feels that children's ability to deal with complex issues is underestimated, citing another primary school where pupils were keen to discuss euthanasia.
His discussion circle is one of several; Newton Mearns is thought to be western Europe's biggest primary, with four P7 classes from which to draw.
Staff flit around the room keeping an eye on things, but are confident to leave their charges alone with the visitors.
Some have distressing stories to tell. A Jewish lady speaks about her experiences of racism: people walking past and in pretending to sneeze, hissing "A Jew!"; a note appearing on her car windscreen telling her that "what happened in the Second World War should happen again". She asks why people behave in such a way and receives earnest answers: because the person is jealous, wants attention, or is showing off.
Two older ladies engender some of the most lively discussion. Pupils are fascinated by how things were different in years gone by, and the guests deal genially with some blunt, unscripted queries. "Do you like being an elderly person?" asks one pupil, to which there is a good-natured reply about the benefits of life experience, with a tinge of wistfulness for lost youth.
Another visitor is talking about mental health, explaining that she carries a "little bag of worries", which, if she did not talk about them, would need a bigger bag.
This prompts a breakthrough with one broody boy sitting with his arms folded tightly, who talks about his difficult relationship with his sister.
Other pupils admit that they are worried about secondary school, but seem encouraged that they might reduce a fear of the unknown into a manageable "bag".
Not all pupils throw themselves into discussion and, in some groups, only one or two pipe up. Yet at times there is an impressive maturity of debate, typified by a lively exchange in a group sitting with a council-lor interested in environmental issues. Later, P7s will also take part in a respect day debate on whether people who contribute to global warming should be fined.
Ann Macbeth, the headteacher, believes that although there are respect day events throughout the school - younger pupils might talk about issues during circle time - P7 has the most intensive sessions. "It does focus the children, and if they take a few things away, it is useful," she says.
"We do other events with the community, but this is a real homing in on issues."