What Did Wesley Mean by "Enthusiasm"?

QUESTION: What does Wesley mean when he thus cautions professors of Christian holiness, "Beware of that daughter of pride, enthusiasm." Is  not enthusiasm a good quality?

ANSWER: In  modern usage it has a good meaning, as it originally had among the Greeks. Take it to pieces and you will And it means en Theos, in God, denoting inspiration. But it soon began to take on the meaning of fanatic, in which sense Wesley used it. Isaac Taylor, in his Natural History of Enthusiasm, says: "A fanatic is an enthusiast transformed or developed. A typical enthusiast has a warm imagination and a sensitive heart with the malignant element still latent." He lives for only one object, and when opposed the evil is apt to become aroused; then he ceases to be an enthusiast and becomes a fanatic, wild, extravagant and unteachable in his religious opinions. He is infallible, being directly inspired by the Holy Ghost, as he imagines. He thinks every thought is from God and that he has no need of the Bible. "Why do I need a guide-board," I heard a fanatic say in a pulpit, "when I have the Guide?" Another boasted that he had not looked in the Bible during a month. The devil easily trips such people up by injecting temptations to evil acts which, not being tested by the Scriptures, are supposed to be right because inspired by God. This is the road to ruin, trodden by many who were once earnest Christians. Wesley cut off sixty fanatics from his Foundry Society in one day. They called him "poor blind John." Beware of fanaticism, the devil's trap for those whom he can catch in no other way.

— Steele's Answers pp. 194, 195.

The Portrait of a Holiness Fanatic

There are two enemies to the fullness of the Spirit — baptized worldliness, and fanaticism run mad on the subject of holiness. Let us consider the latter.

As religion is an exciting and absorbing theme, so there is especial danger of running into unwarrantable enthusiasm. Religious fanaticism has deluged the world with bloodshed, instituted inquisitions, and invented thumbscrews. Sanctification fanaticism is a milder species of this genus, yet it is none the less mischievous. It brings into reproach the most glorious doctrine of the Gospel — the office of the Sanctifier; it brings into ridicule the crowning blessing — the most precious experience of our holy Christianity.

Here is the portrait of a holiness fanatic, or perfectionist.

Give Us a Spiritual Protestantism!

There are multitudes of nominal Christians who confidently assert that it is the highest presumption and folly to expect, in modern times, that full dispensation of the Spirit concerning which so many excellent things are spoken in the Scriptures. They brand as a fanatic the man who proclaims to a slumbering Church the presence of the Holy Ghost, ready to raise the spiritually dead, and to transfigure the spiritually living.