New series 1/3. A lecture series hosted by the Royal Society for the Encouragement of Arts, Manufactures and Commerce (RSA) in London, and chaired by Edward Stourton , featuring speakers who dare to take on received wisdom, whatever the cost. Tonight the philosopher Peter Singer , who has been dubbed "the world's most controversial ethicist", and who wrote an influential book on animal liberation, explains his beliefs and then defends them in discussion with a panel of experts and in response to questions from the audience. Producer Phil Pegum Repeated on Saturday at 10.15pm