 In 2008, Firrell was Public Artist in Residence at St Paul's Cathedral.The residency culminated in "The Question Mark Inside", digital text projections based on blog contributions from members of the public, interviews conducted by the artist with some of the UK's most respected thinkers, and the artist's own observations.Commissioned by Dean and Chapter of St Paul's to mark the 300th anniversary of the topping-out of Christopher Wren's cathedral building, the project aimed to answer the questions