Of this institution, the beginnings are obscure, for it originated in caution and fear; but as the work betrays the workman, and the national physiognomy the native, it is evident that so inquisitorial an act could only have originated in the Inquisition itself.  Feeble or partial attempts might previously have existed, for we learn that the monks had a part of their libraries called the inferno, which was not the part which they least visited, for it contained, or hid, all the prohibited books which they could smuggle into it.  But this inquisitorial power assumed its most formidable shape in the council of Trent, when some gloomy spirits from Rome and Madrid foresaw the revolution of this new age of books.  The triple-crowned pontiff had in vain rolled the thunders of the Vatican, to strike out of the hands of all men the volumes of Wickliffe, of Huss, and of Luther, and even menaced their eager readers with death.  At this council Pius IV. was presented with a catalogue of books of which they denounced that the perusal ought to be forbidden; his bull not only confirmed this list of the condemned, but added rules how books should be judged.  Subsequent popes enlarged these catalogues, and added to the rules, as the monstrous novelties started up.  Inquisitors of books were appointed; at Rome they consisted of certain cardinals and “the master of the holy palace;” and literary inquisitors were elected at Madrid, at Lisbon, at Naples, and for the Low Countries; they were watching the ubiquity of the human mind.  These catalogues of prohibited books were called Indexes; and at Rome a body of these literary despots are still called “the Congregation of the Index.”  The simple Index is a list of condemned books which are never to be opened; but the Expurgatory Index indicates those only prohibited till they have undergone a purification.  No book was allowed to be on any subject, or in any language, which contained a single position, an ambiguous sentence, even a word, which, in the most distant sense, could be construed opposite to the doctrines of the supreme authority of this council of Trent; where it seems to have been enacted, that all men, literate and illiterate, prince and peasant, the Italian, the Spaniard and the Netherlander, should take the mint-stamp of their thoughts from the council of Trent, and millions of souls be struck off at one blow, out of the same used mould.

The sages who compiled these Indexes, indeed, long had reason to imagine that passive obedience was attached to the human character:  and therefore they considered, that the publications of their adversaries required no other notice than a convenient insertion in their indexes.  But the heretics diligently reprinted them with ample prefaces and useful annotations; Dr. James, of Oxford, republished an Index with due animadversions.  The parties made an opposite use of them:  while the catholic crossed himself at every title, the heretic would purchase no book which had not been indexed.  One of their portions exposed a list of those authors whose heads were condemned as well as their books:  it was a catalogue of men of genius.