Eric Gill's Gingerbread Madonna and Child is a small carving in Corsham stone. Gill made the sculpture in 1919, basing it on a drawing by his then 14-year-old daughter Betty, deftly combining the sacred and playful. You can imagine the children of Gill's household cutting out Madonna biscuits like gingerbread men. The sculpture is flat, linear, hieratic, self-consciously primitive, the baby enclosed protectively in its mother's robes. It is a thing of breathtaking beauty and profoundest ambiguity, like so much of Gill's art.
The Gingerbread Madonna is one of many examples of Gill's work assembled for the reopening of Chichester's Pallant House this month. This is a good time to reconsider Gill, a quarter of a century after revelations of adultery, incest and relations with his dog caused a furore in the Catholic press, leading to the Mothers' Union call for the dismantling of his Stations of the Cross in Westminster Cathedral. Since I wrote the biography in question, and since I love his work, I have watched with some anxiety the long-term effect on Gill's reputation. Does consciousness of artists' reprehensible behaviour (Gill in 2006 would no doubt be in prison) put up a barrier between the viewer and the work? Or does knowledge of the artist's life, fallibilities included, amplify and enrich our understanding of the art?
Chichester is the right place for reassessing Gill, since it was his home town. Gill, for all his wildness, was a very small-town person. He lived in Chichester, where his father was a clergyman, through his formative teenage years, the time when this most phallic of artists discovered the unexpected functioning of his own male organ: "What marvellous thing was this that suddenly transformed a mere water tap into a pillar of fire." The impecunious curate's family were crowded into a little terrace house on Chichester's North Walls, and it seems likely that incestuous relations with at least one of Eric's sisters started here.
As a sculptor and engraver Gill balances precariously between the deeply spiritual and provocatively secular. He lurches from frenetic action to repose. This clash of flesh and spirit makes him an infuriating, fascinating man. Whatever his own sins, Gill was not to be deflected from his solemnly idealistic life plan "to make a cell of good living in the chaos of the world". The years in Chichester gave him his strong sense of the enclosed and godly city, bastion against civilisation's many evils. He was to feel the same way about Chartres. Gill responded to this ideal of virtuous apartness in a sequence of notoriously rigorous art and craft communities from which he fulminated against the 20th-century horrors of typewriters, Bird's custard powder, contraception and men wearing the trousers that constricted and degraded "man's most precious ornament".
The striking thing about Gill's work, whether carving, letter-cutting or typography, is his mastery of linear expression. As a young art student, he knew the cathedral in intimate detail, affected most of all by Chichester's remarkable pair of early Norman stone panels carved in relief with biblical scenes. Gill, his emotions always close to the surface, could not look at these carvings without tears. Their influence is obvious on his own characteristically two dimensional carvings: the Westminster Stations; the Creation of Adam panels on the League of Nation's building in Geneva. The strange, ecstatic flatness of such famous wood engravings as Divine Lovers also originated here.
After several years in London, establishing himself as a letter-cutter and monumental mason, Gill was drawn back to Sussex. He was by this time married to Ethel, daughter of the Chichester Cathedral sacristan, and had already committed adultery with their maid-of-all-work Lizzie. "First time of fornication since marriage," he entered in his diary for June 14 1906, prescient of more adulteries to come. He moved his workshop, wife and children to Ditchling, near Lewes, acting out his theories of ideal integration: "Life and work and love and the bringing up of a family and clothes and social virtues and food and houses and games and songs and books should all be in the soup together." He had started making sculpture, rejecting the modelling and pointing machine processes used by the majority of sculptors at this period, preferring the directness of the chisel on the stone.
There is great ebullience in Gill's early work at Ditchling, a true sense of discovery. He was already working at the extremes of the domestic and the risqué; his placid mother and child carvings contrasting with the sheer effrontery of such works as Votes for Women, an explicit carving showing the act of intercourse, woman of course on top. Maynard Keynes bought the carving for £5. When asked how his staff reacted to it, he replied: "My staff are trained not to believe their eyes."
This was also the period at which Gill was making the almost life-size sculpture he entitled Fucking. This carving was over protectively rechristened Ecstasy when bought for the collection at Tate Britain, having been discovered abandoned in a boathouse at Birchington-on-Sea. Is it relevant or is it a distraction to know that the subject of the carving is Gill's younger sister Gladys and her husband Ernest Laughton, entwined in a position of - well - ecstasy, and that Gill's own incestuous relationship with Gladys was then in progress, continuing for most of their adult life? To me it is significant in stressing the artist's dependence on the known and familial: his passion was the personal, he would not use outside models. It certainly deepens understanding of the element of voyeurism in Gill's work.
In 1913, Gill became a Catholic. His father's Church of England was too easy-going for someone with Gill's spiritual and intellectual torments. He craved more strict authority, a degree of flagellation, his sins cast upon the rock that is Christ. Who but Gill would have been carving a life-size marble phallus, its dimensions exactly replicating his own, in the months of instruction leading up to his reception into the church at Brighton? Who else would have decided to leave the relative cosiness of Ditchling Village for Hopkins Crank, an unreconstructed Georgian squatter's cottage and outbuildings on Ditchling Common? As Gill now believed, "there can be no mysticism without asceticism". He became a member of the lay order of the Dominicans and took to wearing the girdle of chastity with his monastic habit. "Much good it did him," a friend said, unconvinced.
The family moved to the Crank with their three daughters, Betty then eight, Petra seven, and Joan, the youngest, three. They stayed on the Common for 11 years, until the girls were in their teens, becoming a kind of Catholic tourist attraction, a marvel of holy poverty in action. The Gill family grouped around the kitchen table, demonstrating the delights of home-killed pig and home-baked bread, was compared by one excited visitor to Holbein's painting of the family of St Thomas More.
The growing girls were kept apart from their contemporaries, educated by their father and mother, enclosed by the routines of the workshops and the chapel. Modern fashions, contemporary mores did not encroach upon a childhood whose simplicity and sweetness is captured in Gill's exquisite series of life drawings of his pubescent daughter Petra. Girl in Bath, the nude teenager crouching in the bath tub, in a pose both homely and potentially erotic; Hair Combing, the girl standing, body plumply outlined against the long cascade of hair; The Plait, which catches the moment when the daughter is almost a woman but not quite. The Petra drawings were reworked as wood engravings and have been for many years among the most admired of all Gill's works.
Do we like them the less knowing, as we know now, that during those years at Ditchling, Gill was habitually abusing his two elder daughters? When in 1980 I came upon the evidence, up to then suppressed, in Gill's private diaries in the University of California at Los Angeles, I cannot say I was totally surprised. The flesh-and-spirit tensions in his work are palpable: this was what had in the first place attracted me to Gill as the subject for critical biography. In his portraits of his children, I was already conscious of a sort of overbalance of tendresse.
The discovery of Gill's precise and candid records in his diaries of his various sexual adventures and experiments was the sort of coup any biographer would long for and yet in some way dread. I knew that it could alter fundamentally perceptions of Gill, both as man of God and as artist. Impossible to view without a frisson, those delicate, delicious portraits of the teenage Petra. Having read Gill's own account of his experimental sexual connections with his dog in a later craft community at Pigotts near High Wycombe, his woodcut The Hound of St Dominic develops some distinctly disconcerting features. The knowing affects the viewing. How can it not? But Gill is too good an artist, too ferocious and intrepid a controversialist, to be protected and glossed over. We need to see him whole.
In 1924, when Gill's affairs in Ditchling had reached a crisis point, he suddenly left Sussex. With his tribal entourage of family and animals, apprentices, dependents, who included the painter David Jones, he settled in the ruined Benedictine monastery at Capel-y-ffin in the Black Mountains of Wales. Here he designed his brilliantly workmanlike typefaces for Monotype, typically throwing his reservations about machine production to the winds. Gill Sans, the sans serif typeface used on the covers of pre-war Penguin books, is rightly lauded in the current V&A Modernism exhibition as the first British modernist type design.
What is striking is that once the immediate commotion over Gill's sexual aberrations had died down, there was a new surge of interest in his work. The 1992 retrospective at the Barbican finally demolished the patronising view of Gill as a Catholic sculptor, setting him in the mainstream of modern British art. The monumental architectural carvings made in Gill's Pigotts period in the 1930s, such familiar elements in the London street scene that they were in danger of being overlooked, emerged with a new clarity. Prospero and Ariel outside the BBC building in Portland Place; the large-scale East Wind sculpture that hovers over St James's Underground station: these are weirdly wonderful examples of Gill's work.
To me, even more moving are Gill's less ambitious carvings way out beyond the city. So many towns and villages are the possessors of one of the carved and lettered war memorials that, after the first world war, were his bread-and-butter line. Gill's workshop was expeditious and prolific. Almost everyone in England has an Eric Gill in reach. Coming unexpectedly across a work by Gill - a carved font in a rarely opened church, a gravestone in a rural cemetery, moss creeping in between the precision-cut Gill letters - is an odd and hauntingly intense experience. These relatively humble works remind us of the extraordinary sureness of his touch. In their offhand way, they celebrate the man who was, by his own account, a stranger in a strange land.
· Modern British Art: The First 100 Years is at Pallant House Gallery, Chichester, until September 24. Fiona MacCarthy will give a talk about Eric Gill there on July 27. Details: 01234 774557