from Gerald Brenan, The Spanish Labyrinth, pp. 251-252
One peculiarity of Spanish Anarchism…was the inclusion within its ranks of professional criminals-thieves and gunmen who certainly would not have been accepted by any other working-class party-together with idealists of the purest and most selfless kind. Occasionally, as we have already pointed out, the two elements were combined in the same person, but more often they were separate. One may explain this historically. The bandit has always been a popular figure in Spain because he preys on the rich and defends the poor. Then during the Napoleonic Wars the guerrilla leader and the bandit fused in the same person. This tradition was continued by the Carlists. Their famous guerrilla leaders, Cabrera, Father Merino, Father Santa Cruz and Cucala, belonged to the same type of men as Durruti and Ascaso. But the Anarchists were also lax in allowing ordinary thieves and murderers to join their organization. The first sign of this was seen during the Cantonalist rising of 1873, when the convict prison of Cartagena, containing 1500 of the most desperate criminals in Spain, was opened on the insistence of the Internationalists and the inmates were invited to join in the defence of the city. Then, during the troubles of 1919 through 1923 at Barcelona, dozens of pure pistoleros entered their ranks. No doubt most of them took care to put a certain ideological colour on their actions, but this would not have been sufficient if the Anarchists had not had a sentimental feeling for all those people who have taken to criminal ways because they have been thwarted or injured by society. A typically Spanish inability to distinguish between those who have enriched themselves by “lawful” means and those who attempt to do so by pure robbery and violence lies at the bottom of this.