Architect Sir Terry Farrell explains why architects are uniquely placed to solve the problems of Britain's public spaces - and why doing the work for free is crucial to its success.

Sir Terry explains how working pro bono can bring together businesses, councils and community groups who would otherwise find it hard to work together, and how these architectural schemes or 'masterplans' can transform the public spaces we all share.

He describes some of the schemes he has worked on - and how, even though it sometimes takes years, the benefits are clear to see.

Producer: Giles Edwards.

Kamin Mohammadi uses her own and her family's history in Iran to argue that life - particularly private life - under an authoritarian regime is lived more creatively.

She describes the complicated and sometimes intricate behaviour which is required to navigate - creatively - around restrictions on private lives. And she explains how everything from the newest technology to shared taxis are called in aid of young people wishing to sit close and steal caresses.

Producer: Giles Edwards.

Entrepreneur Paddy Docherty says business is best placed to bring prosperity to impoverished and post conflict nations, arguing that only the commercial sector can supply the scale and dynamism needed to make a lasting impact on development.

Four Thought is a series of talks with a personal viewpoint recorded in front of an audience at the RSA in London.

Producer: Sheila Cook.

Comedian Kate Smurthwaite argues it's time to stop laughing at sexism and time to stop prejudice against women comedians, because comedy is a key part of UK culture, affecting our opinions and values.

Four Thought is a series of talks with a personal viewpoint recorded in front of an audience at the RSA in London.

Producer: Sheila Cook.

Campaigner Martin Cassini argues that our system for managing traffic is overdue for radical reform and should be based on trust in human nature rather than an obsession with controlling it. He says a drastic cut in the number of traffic lights would begin the transformation, saving lives, time and money.

Writer and former England table tennis champion Matthew Syed says we should not overemphasise the importance of talent over effort.

Four Thought is a series of talks recorded before an audience at the RSA in London.

Producer: Sheila Cook.

Clare Melford, CEO, International Business Leaders Forum, argues that Buddha should be in the boardroom. She explains what CEOs need to learn about the tenets of Buddhism to make their businesses thrive while being

Producer: Sheila Cook.

Professor June Andrews, Director, the Dementia Services Development Centre, University of Stirling, argues for a revolution in our approach to dealing with dementia. She outlines immediate low cost changes that would make a dramatic difference to delaying the onset of the illness and caring for people with dementia.

Jules Evans, author of "Philosophy for Life and Other Dangerous Situations", explores what ancient Greek and Roman philosophy can tell modern society about wellbeing. He celebrates the link between modern psychotherapy and the wisdom of Socrates, the Stoics and other ancient philosophers but warns that the new politics of happiness is in danger of becoming illiberal.

Bobby Cummines, Chief Executive, UNLOCK, the National Association of Reformed Offenders, who served 13 years in high security prisons for robbery and manslaughter, argues if society wants to reduce crime, reformed criminals must be helped to get jobs and discrimination against them needs to stop.

Producer: Sheila Cook.