Three years later, thronged by flashing cameras, Milsom appeared sober, contrite and reflective, as he was announced as the winner of the 2015 Archibald Prize. His prize-winning painting, with the enigmatic title of Judo House pt 6 (the white bird), was a portrait of barrister Charles Waterstreet.

Standing 2.5 metres high and 2 metres wide, the barrister is depicted on a monumental scale, in shades of grey, black and white. The bottom half is black except for two large hands rendered in ethereal streaks of paint.

Says the artist of Waterstreet: "He isn't just a law man. He's a writer, a social environmentalist and is involved in film, photography and theatre too." But, more importantly for Milsom, Waterstreet was his law man. Waterstreet had defended him when the artist stood trial for aggravated armed robbery.

"He put his head on the chopping block and restored my faith in the legal system." At the trial, Milsom pleaded guilty and was sentenced to six years prison, with a minimum of 2½ years.

It seemed cruelly ironic when, only months later, Milsom won the $150,000 Doug Moran Prize. But winning the 2015 Archibald Prize was an entirely different story. Very few in the Australian art world were surprised. One of my artist friends, also a finalist in this year's Archibald, told me, "Milsom had it from the beginning . . . that 'agency beyond the canvas' seems essential for the Archibald." The attraction of Milsom's portrait of his criminal defence lawyer lay well beyond what was depicted on the canvas - it represented a particular story with a certain appeal - not a story of criminality, but of the redemptive capacity of art.

Another redemptive narrative gripped the public imagination three months earlier, in the weeks leading up to the execution of Myuran Sukumaran. Caught smuggling 8.3 kilograms of heroin from Bali in 2005 as part of the Bali Nine, Sukumaran was identified as a ringleader of the operation, along with Andrew Chan, and sentenced to death. While on death row in Kerobokan Prison, Indonesia, Sukumaran asked Ben Quilty, an Archibald Prize winner, to teach him to paint. Quilty agreed and the two became good friends.

In the tense months and weeks leading up to Sukumaran's execution on April 29, Quilty took a leading role in the campaign for clemency, while Sukumaran concentrated more intensely on his art. In the last hours of his life, Sukumaran created some very poignant and powerful works, particularly given his extreme circumstances, including a human heart and an Indonesian flag dripping red. While Chan had found Christianity and was ordained as a minister before his execution, Sukumaran's redemption was seen to lie in his painting. If art could not save his life, it had saved his soul, it seemed.

In our culture, the idea of the redemptive power of art has a particular popular appeal. It's an archetypal narrative that we know even before we hear it. It is what the cultural theorist Roland Barthes calls a "mythology" - not to say that it isn't true, but rather "mythologies" are those stories that fit certain traditional forms that find social and cultural resonance. And redemption is a narrative archetype. Psychologist Dan P. McAdams talks about the importance of "redemptive sequences" in the ways we think about and recall past events in our lives, in which tragic circumstances eventually leads to an emotionally positive outcome. He says the redemption story is "how human beings make narrative sense of suffering in their lives," and how we narrate our past lives has a direct impact on our capacity to cope in the future.

In the context of art, redemption coalesces with another archetypal narrative, that of "catharsis" - an idea that arises with Aristotle and means a purging of the negative, as a process of healing. Expressionist modes of painting are often spoken about in terms of catharsis - think of Edvard Munch's The Scream from 1893, or more recently Quilty's portraits of post-traumatic Afghanistan veterans - possibly because the kinetic energy of the marking and material excess of thick paint feel more desperate, urgent and uncontrolled. Sukumaran's paintings had this.

But in the contemporary art world, we tend to be more cynical about archetypes and accepted narratives in general - these ideas were once dominant in art and often accepted uncritically, but have since been unpacked and dismantled.

But there's no denying that they still have a currency and force in our everyday culture, which is why Milsom's redemption story resonates. Identifying our culture's mythologies and archetypes doesn't mean we no longer believe in them - but if we know why certain narratives appeal, we can also understand how those stories feed into our overall understanding of a work of art, beyond the canvas.

Dr Kit Messham-Muir, senior lecturer in the School of Creative Arts, University of Newcastle, will speak at Exhibit A Symposium at The Lock-up, today from 9.30am