Curator Barbara Ulbrist surveys the art of Martin Firrell focusing on the years 2018-2020. During this time the artist displayed 40 different artworks on billboards across the UK bringing his particular variety of 'art as debate' to the majority of the country's towns and cities.

Firrell put the question, 'What makes your life purposeful and meaningful?' to theologians, scientists, artists, atheists, humanists and the general public. The collected responses, from the domestic to the sexual to the sublime, were project onto the Dome, West Front and Whispering Gallery of St Paul's Cathedral to mark its 300th anniversary.

In an historic first, public art texts are projected onto the front cloth of the Royal Opera House before each act of Puccini's opera 'Tosca'. The artist reveals the opera-like but real-life experiences of jealousy, infidelity and violence in the lives of Ivy, Jeanne, Mary, Leonie, Rita and Isabelle, 6 women aged between 60 and 84.

The Counter Culture Rising series conveys a cinematic story of alien visitation, climate catastrophe and war, artificial intelligence, hippy philosophy and advanced states of consciousness as an antidote to troubled times.

The Skin series was created by the artist in conversation with people from different ethnic backgrounds in celebration of Black History Month.

2019 marked the 40th anniversary of the death of Blair Peach (25 March 1946 - 23 April 1979). Peach was a young white New Zealander, teacher, and liberal killed at an anti-racism demonstration in Southall. 3 billboards for Blair Peach was intended by the artist as the simplest of memorials - naming Blair Peach publicly 40 years after his death.

Based on conversations between the artist and Clare Short (Secretary of State for International Development 1997-2003), the Union City series explores the moral content of socialism.

The Power and Gender series was developed in conversation with 5 women who have experience of power in business, political, or public life. The series examines the difference between the way women and men gain, hold and use power.

Six feminist texts on the nature of power, sexual abuse and social inequality, and the route to gender equality.

The Power and Gender (Men) series examines the changing archetype of masculinity, the impact of social conditioning on men's emotional responses, and the characteristics of power when held by men rather than women.

The Remember 1967 series marks the 50th anniversary of the Sexual Offences Act, which decriminalised, under certain circumstances, sexual relationships between men. The series re-states the demands made by 1960s activists that still warrant action today in the artist's view.

The Sexual Offences Act 1967 partially decriminalised homosexuality in England and Wales. To coincide with the 50th anniversary of the Act, the artist invited 200 senior leaders in business, culture and policy to a Think-In, designed to question traditional gender roles and modelled on the consciousness-raising think-ins pioneered by the Gay Liberation Front in the early 1970s.

'Fires Ancient' projects fire on to the dome of St Paul's in waves of colour consistent with flame of increasing temperatures (from dull orange to yellow to blue to brilliant white). The artwork marks the 350th anniversary of the Great Fire of London.

'Fires Modern' presents 18 histories, or 'metaphorical fires' from the progressive movement as digital projections on to the fly tower of the National Theatre. The series begins with the Lord Mayor's dismissive and inherently misogynist jest that 'the great fire is no threat, a woman could piss it out'.

All Identity examines the premise that everyone's identity is a construction. Some identities may be less usual than others - the self-realisation of trans people for example - but this artwork conveys the idea that every identity is equally and arbitrarily invented.

The Cómo Vivimos portrait series conveys the wisdom of the four eldest inhabitants of the Spanish hill town of Fanzara near Valencia. Their insights are presented as digital projections onto the elders' faces creating composite portraits of inner and outer truth.

It Ends Here is an installation of five underground environments examining power inversion and the cyclical nature of abuse and brutality in the French novel Planete Des Singes (Planet of the Apes) by Pierre Boule, and in the Twentieth Century Fox films based on Boule's work.

I Want to Live in a City Where presents a wish-list of liberal policies as digital projections onto the facade of the National Gallery of Great Britain. The series comprises an ambitious, artist-led agenda for civic agitation and renewal.

Public information systems are re-programmed so that the standard railway station security message is accompanied by the artist's existential 'security message' evoking the burden of loneliness.

Text outlines, performance, info-text, music, found dialogue and internet video clips evoke the UK's LGBT+ language, Polari (a coded language enabling LGBT+ people to express themselves whilst avoiding detection as criminalised homosexuals) and the defiant American drag slang from 1970s New York City drag balls.

The Complete Hero series consists of 18 video portraits, combined with text and graphics, created during the artist's residency with the British Army. The artwork provides a progressive and plural definition of heroism through the eyes of military personnel, scientists, philosophers, writers, comedians and performers.

All Men Are Dangerous was created for Tate Britain against the backdrop of wars in Iraq and Afghanistan, conflicts that were widely held to be colonially motivated and against international law.

In The One Irreducible Truth, the artist paraphrases the renowned American sex researcher Alfred Kinsey who noted that difference in human sexual responses was the only universal constant.

Electronic tills at Borders Books are re-programmed by the artist to add an additional text to the bottom of each till receipt. In this way, thousands of public art texts are brought into circulation during the lifespan of the artwork.

To Understand A Thing Fully Is To Be Able to Say Nothing About It reflects on the nature of understanding and knowledge. Also titled 'L'Éloquence du Silence', the artwork implies that silence must inevitably fall when understanding exceeds the expressive capabilities of language.