THERESA THOMPSON reviews a retrospective at Tate Britain of one this country's greatest — and most controversial painters — Francis Bacon

Visceral is the word that keeps popping up when talking of Francis Bacon. Screaming, snarling mouths, distorted bodies, distracted dogs, gaping apes, grisly figures, frightened or frightening: all take centre stage in his instantly recognisable paintings, demanding our direct and unflinching engagement.

He famously claimed that “the paint comes straight across directly on to the nervous system,” viewing art as a way of opening up areas of feeling rather than merely an illustration of an object. It is totally uncompromising. But it is this quality of Bacon’s strange, often savage work that gives the pictures their power. And nowhere is this more clear than in the huge retrospective of Francis Bacon taking place at Tate Britain. Running until January, it heralds next year’s centenary of the birth of an artist widely acknowledged as one of the 20th century’s greatest painters of the figure.

The Tate has an unrivalled collection of his work. This, their third Bacon retrospective, is the first in the UK since 1985. By any standards, it is a very significant show, says Stephen Deuchar, Tate Britain’s director, with only the very greatest works included.

It features around 65 paintings, including 13 large triptychs, covering the artist’s career and taking us more fully than ever before into the thinking behind his art. This has become possible after a re-assessment of his work following the revelations gleaned from sorting through the wild mass of things left behind in his studio after he died. One eye-opener was the existence of preparatory drawings, something that Bacon had consistently denied making. Several are displayed in the Archive room. The exhibition begins with paintings from the 1940s that bear witness to the shattered psychology of the times, as well as Bacon’s belief that without God man is simply another animal, subject to the same natural urges — of violence, lust and fear — as any other. His screaming pope pictures, including the impressive Head VI (1949) in the first room, signal that religion cannot bring salvation in a godless world.

The decade saw him shoot to fame. Three Studies for Figures at the Base of a Crucifixion, exhibited in London in 1944 alongside works by Henry Moore and Graham Sutherland, brought him instant notoriety. The triptych, showing three twisted semi-human figures on a hot orange ground, evokes the tragedy of the isolated individual, the painting itself anticipating the horrific disclosures shortly to be made of the German concentration camps. Bacon’s Crucifixions — from 1933, 1944, 1962 and 1965 — take up one room in an otherwise broadly chronological show. And what a paradox they present: an atheist obsessed with a subject laden with Christian significance. Bacon claimed that “as a non-believer, it was just an act of man’s behaviour”. He painted the figures, addressing the senseless acts of violence that one human can do to another, not the crucifixion itself.

The central figure of the 1944 triptych is blindfolded and snarling, its mouth apparently inspired by photographs of Nazi leaders speech-making. But the mouth had long fascinated Bacon and became a recurring theme: the silent scream expressing pain, repressed violence or anxiety. Back in 1935 he had bought an illustrated full colour guide to Diseases of the Mouth. Eisenstein's film Battleship Potemkin also had a big effect on him, above all the scene where the nurse cries out on the Odessa steps. As an avid cinema-goer, Bacon drew on details of films as readily as he did on photographs for his source material.

The first rooms introduce other themes. The male nude in all its frailty, as in Study from the Human Body (1949) where a grey figure draws aside a grey veil to step into a dark space; crouching figures, seeming imprisoned in the structure of the picture, boxed in within their ‘space-frames’; the screaming popes, of course; the suited man isolated at a bar (based on a man in a Henley hotel, I’m told), a series from the 1950s reflecting the world of seedy bars and gay pickups, and the ongoing illegality of homosexuality; and later the triptychs and smaller paintings memorialising his lover George Dyer.

Bacon based much of his earlier work on the Old Masters he admired, Velázquez above all. The Archive room shows torn art magazine or book pages rescued from his studio, the paint splotched inspirations, for example for Study after Velázquez's Portrait of Pope Innocent X (1953), an image he developed over and again, and the gaudy Study for Portrait of Van Gogh VI (1957), criticised for its “reckless energy” and later considered an aberration. So far so objective. Now for the subjective. In terms of getting to know Bacon or reappraising him, this is a great exhibition and very well presented. In personal terms, whereas Bacon had left me cold before, now 65 or so pictures and an elucidating archive later, I hadn’t quite changed my mind but understood more the context of that unremitting misery, that distortion.

To see Bacon is to share the pain of these anguished souls, animal and human. Like it or not, his visceral view of the human condition does jag those nerves. But as retrospectives go this is as good as it gets, and it clearly shows what a great colourist this totally untutored artist was.

The Francis Bacon restrospective is at the Tate Britain until January 4, 2009. For further information visit the website: www.tate.org.uk