Now I have taken these two or three examples of the earlier medieval movements in order to note about them one general character, which refers back to the penance that followed paganism. There is something in all these movements that is bracing even while it is still bleak, like a wind blowing between the clefts of the mountains. That wind, austere and pure, of which the poet speaks, is really the spirit of the time, for it is the wind of a world that has at last been purified. To anyone who can appreciate atmospheres there is something clear and clean about the atmosphere of this crude and often harsh society. Its very lusts are clean; for they no have longer any smell of perversion. Its very cruelties are clean; they are not the luxurious cruelties of the amphitheatre. They come either of a very simple horror at blasphemy or a very simple fury at an insult. Gradually against this grey background beauty begins to appear, as something really fresh and delicate and above all surprising. Love returning is no longer what was once called platonic but what is still called chivalric love. The flowers and stars are have recovered their first innocence. Fire and water are felt to be worthy to be the brother and sister of a saint. The purge of paganism is complete at last.
For water itself has been washed. Fire itself has been purified as by fire. Water is no longer the water into which slaves were flung to feed the fishes. Fire is no longer that fire through which children were passed to Moloch. Flowers smell no more of the forgotten garlands gathered in the garden of Priapus; stars stand no more as signs of the far frigidity of gods as cold as those cold fires. They are like all new things newly made and awaiting new names, from one who shall come to name them. Neither the universe nor the earth have now any longer the old sinister significance of the world. They await a new reconciliation with man, but they are already capable of being reconciled. Man has stripped from his soul the last rag of nature worship, and can return to nature.
-- From Saint Francis
I think this is one of Chesterton's most remarkable passages. It occured to me today as I was thinking about the Christian Anglo-Saxon poetry of Caedmon and The Dream of the Rood. When I think of those poems, of the whole spiritual and mental world preserved in them, the epithet that leaps to mind is clean. There is a freshness, a naivety, a Spring-time youthfulness in them, as though the sun and moon had been new-minted and a dew lay over all Creation. They seem to belong to a world so much younger and heartier than the Roman Empire.
Chesterton was certainly a man who could "appreciate atmospheres". I think this might be his very greatest gift. He had the most astounding ability to take the pulse of an era, a nation, or an environment. It is to be seen in his description (in Orthodoxy) of the pre-Christian world as a place grown sick and weary of the "Inner Light", or his insight (in The Everlasting Man) that the myths and legends of pagan cultures were hardly believed by anybody, or his diagnosis of Theosophistic and esoteric cults as a hierarchy of mysteries whose ultimate mystery is that there is no God.
Sometimes I think his sensitivity to atmosphere was even, perhaps, what led him astray. His staunch support for World War One came mostly from a horror of what he called "Prussianim", which he saw as an anti-chivalric, anti-Christian, bullying philosophy of Blood and Iron that would corrupt the soul of Europe if permitted. I do not know if he was right; but it seems a very abstract motivation for an unspeakably bloody war.