Inspired by the amazing Picasso exhibition at Tate Modern, I've been reading James Attlee's recent book Guernica: Painting the End of the World – which not only tells the remarkable history of the 1937 masterpiece's genesis and long afterlife, but also tries to unravel its powerful symbolism.
Picasso, of course, was not one to be drawn on what his paintings 'meant'. When he curated his own retrospective in 1932, he deliberately mixed up works from all of his different periods and supplied no information with any of them.
Guernica, produced five years later, was an exception in that it was clearly a howl of protest against Spain's fascists allowing Germany to test its weapons of mass destruction on a defenceless Basque village.
But there is much more in this bleak black, white and grey canvas, the monochromatic approach itself suggesting a photograph, a snapshot of horror.
Some elements in the painting seem to be interior, some exterior; buildings have been ripped asunder, breaking the boundaries between the inside and outside of homes – as happens in bombings.
An anguished mother cradles her dead baby; a dismembered soldier lies on the ground; a wounded horse with a gaping wound in its side is in agony; a woman screams as she falls from a burning building. These seem easy to read – other elements are not.
The central light in the sky was originally intended by Picasso to be the sun, but he changed it to an electric light: perhaps a comment on the new technology being deployed in all aspects of life – and now of death. In passing, Attlee points out that the word for a light bulb in Spanish is bombilla, not that much different to bomba, for bomb.
Paradoxically, the sun/electric light/new tech appears to spread no light in the painting. Instead, it is an alarmed woman with an old-fashioned lamp leaning out of a window who provides it.
Attlee relates this to the lantern in Goya's The Third of May 1808, a painting Picasso knew well, and which illuminates a man about to be shot by firing squad. 'The lantern is death,' said Picasso of the Goya. But the light-bringer also symbolically offers truth – and an illumination that the artificial light cannot.
One of the most disturbing images of Guernica is the inclusion of a dove-like bird – which should be a symbol of peace, but which here is darkened and squawking in fear and terror.
The bull and the horse are Guernica's most heavily laden symbols. Together they are representative of the bullfight, a potent totem both for Spain and for Picasso. Eternally caught up in the suffering of the corrida, the bull and horse can also represent the domestic animals slaughtered, along with their owners, at Guernica.
It has been argued as well that the wounded horse represents the Spanish nationalists, and the defiant bull the republicans – or possibly the bull is Picasso himself. But Attlee suggests convincingly that the bull is actually 'the witness' in this painting, the one figure that sees the horror and demands that you look at it too – just as two horses are witness to human carnage in Goya's The Second of May 1808 (companion piece to The Third of May 1808).
Picasso said that it was ultimately up to the viewer to decide on all meaning. However, as Attlee's subtitle makes clear, Guernica was – and still is – a dreadful vision of the end of humanity. Picasso painted it before the Holocaust, before Vietnam and 9/11 and Iraq and Syria – but they are all here in this terrible warning. And so, one fears, is our future…
Guernica: Painting the End of the World by James Attlee (Head of Zeus, £18.99)
Picasso 1932 – Love, Fame, Tragedy at Tate Modern until 9th September; www.tate.org.uk