The Philosophy of Natural Magic, by Henry Cornelius Agrippa, L. W. de Laurence ed. , at sacred-texts.com
That the proper names of things are very necessary in Magical Operations, almost all men testify. For the natural power of things proceeds, first, from the objects to the senses, and then from these to the imagination, and from this to the mind, in which it is first conceived, and then is expressed by voices and words. The Platonists, therefore, say that in this very voice, or word, or name framed, with its articles, that the power of the thing, as it were some kind of life, lies under the form of the signification. First conceived in the mind, as it were through certain seeds of things, then by voices or words, as a birth brought forth; and lastly, kept in writings. Hence magicians say, that the proper names of things are certain rays of things, everywhere present at all times, keeping the power of things, as the essence of the thing signified, rules, and is discerned in them and know the things by them, as by proper and living images. For, as the great operator doth provide divers species and particular things by the influence of the Heavens, and by the elements, together with the virtues of planets, so, according to the properties of the influences, proper names result to things and are put upon them by him who numbers the multitude of the stars, calling them all by their names; of which names Christ in another place speaks, saying, "Your names are written in Heaven." Adam, therefore, that gave the first names to things, knowing the influences of the Heavens and properties of all things, gave them all names according to their natures, as it is written in Genesis, where God brought all things that he had created before Adam, that he should name them; and as he named any thing, so the name of it was; which names,
indeed, contain in them wonderful powers of the things signified. Every voice, therefore, that is significative, first of all signifies by the influence of the celestial harmony; secondly, by the imposition of man, although oftentimes otherwise by this than by that. But when both significations meet in any voice or name, which are put upon them by the said harmony, or men, then that name is with a double virtue, viz., natural and arbitrary, made most efficacious to act as often as it shall be uttered in due place and time, and seriously, with an intention exercised upon the matter rightly disposed, and that can naturally be acted upon by it. So we read in Philostratus, that when a maid at Rome died the same day she was married, and was presented to Apollonius, he accurately inquired into her name, which being known, he pronounced some occult thing, by which she revived. It was an observation amongst the Romans, in their holy rites, that when they did besiege any city, they did diligently enquire into the proper and true name of it, and the name of that God under whose protection it was; which being known, they did then with some verse call forth the Gods that were the protectors of that city, and did curse the inhabitants of that city, so at length, their Gods being absent, did overcome them, as Virgil sings:
Now the verse with which the Gods were called out and the enemies were cursed, when the city was assaulted round about, let him that would know find it out in Livy and Marcrobius; but also many of these Serenus Samonicus, in his book of secret things, makes mention of.