one invisible and indestructible hair

Every heresy has been an effort to narrow the Church. If the Franciscan movement had turned into a new religion, it would after all have been a narrow religion. In so far as it did turn here and there into a heresy, it was a narrow heresy. It did what heresy always does; it set the mood against the mind. The mood was indeed originally the good and glorious mood of the great St. Francis, but it was not the whole mind of God or even of man. And it is a fact that the mood itself degenerated, as the mood turned into a monomania. A sect that came to be called the Fraticelli declared themselves the true sons of St. Francis and broke away from the compromises of Rome in favour of what they would have called the complete programme of Assisi. In a very little while these loose Franciscans began to look as ferocious as Flagellants. They launched new and violent vetoes; they denounced marriage; that is, they denounced mankind. In the name of the most human of saints they declared war upon humanity. They did not perish particularly through being persecuted; many of them were eventually persuaded; and the unpersuadable rump of them that remained remained without producing anything in the least calculated to remind anybody of the real St. Francis. What was the matter with these people was that they were mystics; mystics and nothing else but mystics; mystics and not Catholics; mystics and not Christians; mystics and not men. They rotted away because, in the most exact sense, they would not listen to reason. And St. Francis, however wild and romantic his gyrations might appear to many, always hung on to reason by one invisible and indestructible hair.
 -- St Francis 1923, G K Chesterton

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