HEROISM HAS PREOCCUPIED philosophers and storytellers from the time of the earliest folk tales. From Plato to Shakespeare, Cervantes to Conrad, writers have long wrestled with the question of what makes a hero, and whether the term necessarily equates with acts of gallantry, martyrdom or extreme daring. How should we measure the self-sacrifice of ordinary Joes quietly doing good works or of nameless soldiers slain on the fields of long-forgotten battles against the overtly chivalrous acts of Robin Hoods or the impetuous bravery of spontaneous 'heroes' who risk injury or death by rescuing total strangers from armed assailants or blazing infernos?

These and related issues lie at the heart of Soldiers of Salamis, Javier Cercas's novel about the scrappy, rancorous legacy of the Spanish Civil War. The subject of this ambitious, if slender, book is the mystery surrounding an inexplicable act of human charity that allowed one of Franco's senior Nationalist lieutenants to survive a firing squad not once but twice in the space of a single hour.

Rafael Sanchez Mazas was a poet and a political theorist, one of the founding fathers of Falangism. In the dying days of the Civll War, he and forty-nine other prominent Nationalists were rounded up