Criminologist David Wilson looks at 17th century philosopher Thomas Hobbes and his "social contract" theory. Hobbes argued that the only way to secure peace was for everyone to give up their personal freedom and agree to be ruled by a "sovereign". Otherwise, he said, life was liable to be "nasty, brutish and short", with everyone at war with everyone else.

In fact, none of us has actually signed a contract to give up our freedom, so what if we disagree with what the state wants to do? David looks at the case of the "naked rambler", Stephen Gough, who is currently in Winchester prison because he refuses to wear clothes in public. Gough benefits from the protection of the state, so is he obliged to stick to social norms as his part of the bargain?

David also looks at "bitcoins" - the digital currency that operates outside the control of any government. Is bitcoin world a libertarian utopia, or a reminder of what Hobbes was talking about: that without someone to lay down the law, you end up with violence and rampant criminality?

Presenter: David WilsonProducer: Jolyon Jenkins.