Huh: that link points to the same book that I referenced in my comment!

He wrote about the front: “Up here in Aragon one was among tens of thousands of people, mainly though not entirely of working-class origin, all living at the same level and mingling on terms of equality. In theory it was perfect equality, and even in practice it was not far from it.”

Are you talking about the rise of the Popular Army?

For the time being, however, the militias were holding the line while the Popular Army was training in the rear, and this fact had to be advertised as little as possible. Drafts of militia returning to the front were no longer marched through the streets with drums beating and flags flying. [] The fact that the militia troops were also, on paper, Popular Army troops, was skilfully used in the Press propaganda. Any credit that happened to be going was automatically handed to the Popular Army, while all blame was reserved for the militias.

[] When I first reached Barcelona I had thought it a town where class distinctions and great differences of wealth hardly existed. [] ‘Smart’ clothes were an abnormality, nobody cringed or took tips, waiters and flower-women and bootblacks looked you in the eye and called you ‘comrade’. I had not grasped that this was mainly a mixture of hope and camouflage. [] Now things were returning to normal. The smart restaurants and hotels were full of rich people wolfing expensive meals, while for the working-class population food-prices had jumped enormously without any corresponding rise in wages. Apart from the expensiveness of everything, there were recurrent shortages of this and that, which, of course, always hit the poor rather than the rich. The restaurants and hotels seemed to have little difficulty in getting whatever they wanted, but in the working-class quarters the queues for bread, olive oil, and other necessaries were hundreds of yards long. Previously in Barcelona I had been struck by the absence of beggars; now there were quantities of them. [] The workers’ patrols had been ordered to dissolve and the pre-war police forces were back on the streets. One result of this was that the cabaret show and high-class brothels, many of which had been closed by the workers’ patrols, had promptly reopened.

More about his political views being formed from being on the front:

One had been in a community where hope was more normal than apathy or cynicism, where the word ‘comrade’ stood for comradeship and not, as in most countries, for humbug. One had breathed the air of equality. I am well aware that it is now the fashion to deny that Socialism has anything to do with equality. In every country in the world a huge tribe of party-hacks and sleek little professors are busy ‘proving’ that Socialism means no more than a planned state-capitalism with the grab-motive left intact. But fortunately there also exists a vision of Socialism quite different from this. The thing that attracts ordinary men to Socialism and makes them willing to risk their skins for it, the ‘mystique’ of Socialism, is the idea of equality; to the vast majority of people Socialism means a classless society, or it means nothing at all. And it was here that those few months in the militia were valuable to me. For the Spanish militias, while they lasted, were a sort of microcosm of a classless society. In that community where no one was on the make, where there was a shortage of everything but no privilege and no boot-licking, one got, perhaps, a crude forecast of what the opening stages of Socialism might be like. And, after all, instead of disillusioning me it deeply attracted me. The effect was to make my desire to see Socialism established much more actual than it had been before. Partly, perhaps, this was due to the good luck of being among Spaniards, who, with their innate decency and their ever-present Anarchist tinge, would make even the opening stages of Socialism tolerable if they had the chance.

You might want to read his memoirs on the subject.