States of ecstasy (from the ancient Greek ekstasis, meaning 'standing outside') are moments when you lose your ordinary sense of self and feel connected to something greater than you. It can be euphoric, but it can also be terrifying, says the philosopher Jules Evans. Here he selects five books that explore the significance and power of these surprisingly common experiences.

"Time is an illusion," wrote Douglas Adams. "Lunchtime, doubly so." It is certainly a subjective experience, agrees the psychologist and author Marc Wittmann—as any drug user or meditation expert can tell you. Here he picks five books that unpick our perception of the passage of time.

Everything we have been told about drugs and drug addiction and how society should deal with them is wrong, says the British author and journalist Johann Hari. He chooses the best books on 'the war on drugs.'

The social historian argues London is an intrinsically addictive city. He charts its history through its dependencies on chocolate, tobacco, coffee, and tea.

The Italian cardiologist and fellow of the International Association for Cannabis as Medicine proposes five books on Medicinal Marijuana and explains why we should be reading them.