For example, here he is discussing David Hume:
Who has not heard of David Hume? Cui non notus Hylas? Taking every thing into consideration, I do believe that the eighteenth century, so remarkably productive of infidelity, never gave birth to so heartless and inveterate an enemy to the Church of Christ. . . .
Let us suppose that Hume had been condemned to death, or even arraigned at the bar of his country, for one of those crimes which, according to the black statute book, are punishable with death; would not many of those offences which that code deems capital, (for instance, the stealing of a sheep, or any article of the value of a shilling) be less criminal, in the eyes of eternal Justice, than his demoralizing works, wherein he so obstinately and impiously attacks the most sacred dogmas of natural and revealed religion, and whereby he endeavors to convulse and confound the Christian universe? Even with such an impression on their minds, I am satisfied that the Protestant and truly fallible head of the English Church, and his ministerial parliament, would not refuse the dedicatory homage of this infidel’s history.
Anyway, the book is a defense of the Spanish Inquisition. Maistre’s argument is that the Church was not responsible for any excesses that may have occurred during the Inquisition. Instead, he makes clear that the Inquisition was conducted by the Spanish state. Further, he argues that the Inquisition was just – his argument here isn’t all that different from much modern scholarship. Finally, he argues that the Inquisition saved the Spanish state from the consequences Protestantism in other countries (think 30 years war, french revolution, english civil war, etc.).
He does all this with remarkable style. Here is his argument in a nutshell:
Truth must never compromise; otherwise it would change its nature and its name. The toleration of error, in religious concerns, would be its ruin. The Inquisition, therefore, being a protective law of the only religion of Spain, the introduction of religious error, or heresy, must be considered a species of counterfeit, or contraband goods — a pleasing but poisonous drug, which, by defeating or destroying the law, would ruin the industry, comfort, happiness, and lives, of all who are benefited by the law. It is, therefore, the duty of the sovereign to see the law respected; but, should his civil agents transcend its prescribed limits, the law, or the monarch, and, least of all, the religion, of the nation and of the Catholic world, should not be censured for it.
It is incumbent on the modern reactionary to try to understand how people who are long dead thought. This task is quite difficult. Maistre thinks very differently than anyone alive today. On the modern political spectrum Maistre is so far to the right as to be almost incomprehensible. I don’t think it a stretch to say that he would be physically repulsed by modern society. His arguments are interesting in that they provide a nice glimpse into this long-lost mindset.