A journalist, describing in the Daily News an interview with Chesterton, includes this delightful tidbit:

At this [Chesterton] drew his basket chair menacingly nearer to me, and I drew my chair nearer to him, while for an hour or more we hurled defiance at each other's creeds. I continued the struggle with indomitable perseverance until he had proved, to my satisfaction and his own exuberant delight, that my Protestantism was merely undeveloped Vaticanism. When, however, he proceeded to disprove my existence, which I value, I ventured to change the subject.

-December 13, 1907, Daily News, "'G.K.C.' at Home"

British author Terry Deary, on being asked which book "would you take to a desert island", replied

I never tire of The Napoleon Of Notting Hill by G.K. Chesterton. A book written in technicolour. [Source]

While reading through the Bible the other day, I came across a verse that seems to me to perfectly describe Chesterton, What I mean is that Chesterton's humility and charity was such that so many people who were his greatest enemies on an intellectual level (such as H.G. Wells and George Bernard Shaw, for instance, whom he often debated), nevertheless greatly loved Chesterton and were close friends with him on a personal level. And such seems to me to be an example of this proverb:

"When a man's ways please the LORD, he makes even his enemies to be at peace with him." (Proverbs 16:7)

"I reckon you'll be shocked," replied Greywood Usher, "as I know you don't cotton to the march of science in these matters. I am given a good deal of discretion here, and perhaps take a little more than I'm given; and I thought it was an excellent opportunity to test that Psychometric Machine I told you about. Now, in my opinion that machine can't lie."

"No machine can lie," said Father Brown, "nor can it tell the truth."

"It did in this case, as I'll show you," went on Usher positively. "I sat the man in the ill-fitting clothes in a comfortable chair, and simply wrote words on a blackboard; and the machine simply recorded the variations of his pulse; and I simply observed his manner. The trick is to introduce some word connected with the supposed crime in a list of words connected with something quite different, yet a list in which it occurs quite naturally. Thus I wrote 'heron' and 'eagle' and 'owl,' and when I wrote 'falcon' he was tremendously agitated; and when I began to make an 'r' at the end of the word, that machine just bounded. Who else in this republic has any reason to jump at the name of a newly arrived Englishman like Falconroy except the man who's shot him? Isn't that better evidence than a lot of gabble from witnesses: the evidence of a reliable machine?"

"You always forget," observed his companion, "that the reliable machine always has to be worked by an unreliable machine."

"Why, what do you mean?" asked the detective.

"I mean Man," said Father Brown, "the most unreliable machine I know of. I don't want to be rude; and I don't think you will consider Man to be an offensive or inaccurate description of yourself. You say you observed his manner; but how do you know you observed it right? You say the words have to come in a natural way; but how do you know that you did it naturally? How do you know, if you come to that, that he did not observe your manner? Who is to prove that you were not tremendously agitated? There was no machine tied on to your pulse."

"I tell you," cried the American in the utmost excitement, "I was as cool as a cucumber."

"Criminals also can be as cool as cucumbers," said Brown with a smile. "And almost as cool as you."

"Well, this one wasn't," said Usher, throwing the papers about. "Oh, you make me tired!"

"I'm sorry," said the other. "I only point out what seems a reasonable possibility. If you could tell by his manner when the word that might hang him had come, why shouldn't he tell from your manner that the word that might hang him was coming? I should ask for more than words myself before I hanged anybody."

-The Wisdom of Father Brown (1914)

Thus the Sacrament of Penance gives a new life, and reconciles a man to all living, but it does not do it as the optimists and the hedonists and the heathen preachers of happiness do it. The gift is given at a price, and is conditioned by a confession. In other words, the name of the price is Truth, which may also be called Reality; but it is facing the reality about oneself. When the process is only applied to other people, it is called Realism.

-Autobiography (1936)

Imperialism is not an insanity of patriotism; it is merely an illusion of cosmopolitanism.

-Irish Impressions (1919)

"...they are not submitting a variety of actions to one test; they are applying a variety of tests to one action,"

People will make attempts at despotism, or demands for freedom, successively or even simultaneously, according to a quite arbitrary program of opportunism. And we feel that they are not submitting a variety of actions to one test; they are applying a variety of tests to one action, which is for them already a fixed and settled action. They do what they want, and make up reasons for it afterwards; but even the reasons are rather too cunning to be reasonable. In a word, it is this chaos, in the creed and code of conduct, that prevents a man from finding in it any sort of guide, even a guide to progress.

-All I Survey (1933)

A friend has sent me a sort of guide or prospectus of the food eaten by vegetarians, or, to speak more strictly, I believe, by fruitarians. It has given me more solid pleasure than any book of poetry or philosophy I have read for years. Not that I want to eat the fruitarian foods; Heaven forbid. A man may be interested in the ingenuity and picturesqueness of a scheme of advertisement without having the desperate design of sampling any of the wares. Suppose I had lived in Renaissance Italy, I might have received some pleasant little pamphlet such as this, advertising "Borgia Biscuits; the best for Bishops"; or, "Try Lucrezia, the Latest Soporific; Invariably Ends an Illness"; or, "Pope Alexander's Painless Chianti: the late Cardinal Colonna writes 'Since then I have used no other.' "

In such a case I should order tones of the entertaining prospectus, but none of the food. I feel almost an equal degree of fastidiousness about the Fruit Foods, some of which sound to me as ominous as Borgia Biscuits.

-December 4, 1909, Illustrated London News

Heathenism held the individual as a mere muscle of the State; scepticism is restoring the conception. Therefore the modern sociologists are already beginning to dabble in that dreadful idea of which the old pagans drank deep. I mean Infanticide. Christianity stands in history between them, demanding justice though the heavens fall; and he that is not with her is against her.

-April 9, 1910, Daily News

No one worth calling a man allows his moods to change his convictions; but it is by moods that we understand other men’s convictions. The bigot is not he who knows he is right; every sane man knows he is right. The bigot is he whose emotions and imagination are too cold and weak to feel how it is that other men go wrong.

-Alarms and Discursions (1910)

When we really wish to know how the world is going, it is no bad test to take some tag or current phrase of the press and reverse it, substituting the precise contrary, and see whether it makes more sense that way. It generally does; such a mass of outworn conventions has our daily commentary become.

-The Well and the Shallows (1935)

But when we are quite sure that we rejoice in a nation's strength, then and not before we are justified in judging its weakness.

-What I Saw in America (1922)