Deckherri - Conjecturae - 1686

Trial against the authors: Johannes Deckherr and the art of unmasking the fakes
Johannis Deckherr's work is situated at the heart of the great era of late 17th-century critical erudition, when philology, history, and law began systematically dismantling false attributions, spurious epistles, and fictitious authorities that had dominated European knowledge for centuries. De Scriptis adespotis, pseudepigraphis et supposititiis is not merely a repertory but a true textual tribunal, where every anonymous or suspicious writing is interrogated, contextualized, and judged. This expanded and corrected third edition reflects methodological maturation and an expanded scope of investigation, confirming the volume as a fundamental tool for theologians, jurists, physicians, and philosophers.
Market value
In the European antique market, the sixteenth-century editions of Deckherr are rare and sought after, especially in academic-specialist circles. Complete and well-preserved copies of the third edition from Amsterdam 1686 generally range between 1,500 and 2,500 euros, with higher prices for copies in a well-preserved coeval binding and with a good margin. The value is supported by the methodological importance of the work and its role as a reference in the history of textual criticism.

Physical description and condition
Contemporary full brown leather binding, with a spine decorated with ribs. Bicolour red and black frontispiece, with physiological stains and browning. In ancient books, with a multi-century history, some imperfections may be present, not always noted in the description. Pp. (6); 12nn; 412; 16nn; (8).

Full title and author
Of the writings attributed falsely, pseudepigraphic, and fictitious conjectures, with additions from various sources.
Amsterdam, at Isbrandus Haring's, 1686.
Johannis Deckherri

Context and Significance
Deckherr addresses one of the most delicate issues in European culture: the authority of the text. Through a vast survey of anonymous, pseudonymous, or falsely attributed writings, the author questions accepted tradition by applying historical, stylistic, and documentary criteria. The work moves across theology, law, medicine, and philosophy, showing how anonymity is not neutral but often a tool for polemics, propaganda, or dissimulation. Particularly significant is the use of 'coniectura' as a method, which anticipates modern forms of internal and comparative criticism. In this sense, the volume represents a crucial step in the shift from authority by tradition to authority by verification.

Biography of the Author
Johannes Deckherr, active in the 17th century, was a jurist and judge of the Imperial Chamber in Spira, as well as a lawyer and prosecutor. His legal training profoundly influenced his scholarly approach: texts are treated as evidence, authors as defendants, and history as a courtroom. Deckherr belongs to that generation of scholars who played a decisive role in the birth of modern critical philology.

Printing history and circulation
The first edition of the work appeared in the second half of the seventeenth century, followed by expanded editions that attest to its success and continued use as a reference manual. The Amsterdam 1686 edition, printed by Isbrand Haring, is considered one of the most complete, with numerous additions and corrections. The choice of Amsterdam as the place of printing reflects the city's central role as a free and international publishing hub, particularly suitable for works of strong critical nature and potentially controversial.

BIBLIOGRAPHY AND REFERENCES
C. G. Kayser, the most comprehensive index of books pertaining to universal knowledge.
J. A. Fabricius, Bibliotheca Latina.
J. Le Clerc, Ars critica.
BnF and WorldCat catalogs, entries Deckherr Johannes.
Studies on the history of pseudepigraphy and textual anonymity in the 17th century.