To continue my blogs on Jesuits writings on the occult and arcane, today I have a sammelband of two books by Petrus Thyraeus SJ.

682J Petrus Thyraeus (1546–1601)

Daemoniaci, hoc est: De obsessis a spiritibus daemoniorum hominibus, liber unus: in quo Dæmonum obsidentium conditio: obsessorum hominum Status; rationeel & modi, quibus ab Obseßis Dæmones exiguntur: causæ item tune fifficilis exitus ipsorum, tum signorom quæ exituri relinquunt: locoa demique, quo egreßi tendunt, & his similia, discutiuntur & explicantur.

bound with

Loca infesta, hoc est: de infestis, ob molestantes daemoniorvm et defvnctorvm hominvm spiritvs, locis, liber vnvs:in quo spirituum infestantium genera, conditiones, vires, discrimina, opera, mala quae viventibus afferunt ; rationes item quibus partim cognoscuntur, partim proscribuntur ; modi denique, quibus loca ab ipsorum molestia liberntur, his’que similia discutiuntur & explicantur. Accessit eiusdem Libellus de terricvlamentis nocturnis quae hominum mortem solent portendere.

)both( Coloniae Agrippinæ: ex officina Mater, Cholini, sumptibus Gosuini Cholini, 1598. . $5,700

Two Quarto volumes bound as one. 19.7 x 15.5 cm. Signatures ad I. (:)4(:)(:)², A-Z4 Aa-Bb4,Cc².  ad II. (:)⁴ (:)(:)⁴, A-Xx⁴ Bound in full vellum binding with gilt title on spine label; ownership notes, some of which deleted, on the title page of the first work. age toning throughout due to bad paper.

The Dæmonici is considered among the first scientific attempts to explain as well as define demonic possession (“obsession”) and exorcism .


The Local Infesta is an encyclopedia of Haunted and evil places including Purgatory, Hell and the Underground.

Daemoniaci is comprised of 58 Disputation divided into three sections in which he identifies the behavior “symptoms’ of which are and aren not indicative of dæmons , these are quite amusing analysis of deviant and not so deviant human behaviors, including , sleeping late, unpleasant demeanor or the speaking in unidentifiable languages or desiring raw meat.

Loca Infesta, is an encyclopedia of locals infested by deamons and malefactors, Thyæo relies upon not only historical authors such as Aristotle ,Moyses and Virgil but also modern (contemporary to him) authors including protestant, jews and heretics , Including Zwingli, Melanchthon,Cardanu. This work provides a comprehensive view of the various places and types of demonic infestations that were believed to exist during Thyæo’s time. It is a fascinating read for those interested in the history of demonology and exorcism.

Belowtable of contents from the Dæmoniaci


ad I: DeBacker/Sommervogel vol. VIII col. 15 nº15.; BM STC Ger. C16th. p. 862. ; Caillet 10687.; Thorndike VII 368-9 (VD 16) T 1238.

ad II. DeBacker/Sommervogel vol. VIII col. 16 nº20; USTC 673124; Adams, T700; BnF FRBNF31468196; (VD 16) T 1247.