Placidus de Titis (also de Titus, Latinization of Placido de Titi, pseudonym Didacus Prittus Pelusiensis; 1603–1668) was an Olivetan monk and professor of mathematics, physics and astronomy at the University of Pavia from 1657 until his death. Placidus popularized the system of astrological houses now known as the "Placidian system", current in modern astrology. He did not invent the method; it is acknowledged by the 12th century Hebrew astrologer Abraham Ibn Ezra as the system employed by Ptolemy, an attribution that was accepted by Placidus.

Placidus de Titis
Physiomathematica, sive Coelestis philosophia naturalibus hucusque desideratis ostensa principijs, 1650
Born(1603-12-25)25 December 1603
Died1668(1668-00-00) (aged 64–65)
Pavia, Lombardy, Italy
Other namesDidacus Prittus Pelusiensis
Occupation(s)Monk, mathematician, astronomer, astrologer
Known forPlacidian system
Parent(s)Tiberio Titi and Cecilia Titi
Academic background
Alma materUniversity of Padua
Influences
Academic work
InstitutionsUniversity of Pavia
Notable students
Influenced

Biography

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Placidus was born in Perugia, into the Titi noble family. His father died early, and he was looked after by his mother Cecilia. He studied at the University of Padua where his uncle Girolamo de Titi was professor of theology. One of his teachers was the astronomer Andrea Argoli. The Duchy of Milan at the time was owned by Habsburg Spain, administered by Archduke Leopold Wilhelm of Austria. The Archduke showed strong interest in science, especially occult sciences of alchemy and astrology, and Placidus dedicated his astrological house tables to him. In 1657 he was appointed professor of mathematics at the University of Pavia, a position he held for the rest of his life. Like his contemporary Jean-Baptiste Morin, Placidus opposed the copernican theory and retained a geocentric perspective, although there have been suggestions that he might have been a closet Copernican.[4]

He died in Pavia in 1668.

English translations of Placidus' Primum Mobile were published by Manoah Sibly (1789) and John Cooper (1814).

Works

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  • De motibus directionum coelestium mobilium (1641).
  • Physiomathematica sive coelestis philosophia (1650), Placidus' magnum opus, first published as Quaestionum physiomathematicarum libri tres, under the pseudonym of Didacus Prittus Pelusiensis, second edition by C. Francobacci und A. Scirota (pseudonyms of two of Placidus' students, F. Brunacci and F. M. Onorati).
  • Physiomathematica, sive Coelestis philosophia naturalibus hucusque desideratis ostensa principijs (in Latin). Milano: Giovanni Battista Malatesta. 1650.
  • Nuncius astronomicus (1654).
  • Il corriere astronomico (1656).
  • Tabulae primi mobilis cum thesibus et canonibus (1657).
  • Commentaria in Ptolemaeum de siderum judiciis (1658).
  • De siderum judiciis, 2 vols. (1660, 1665).
  • Ephemeridum caelestium motuum (in Latin). Pavia: Giovanni Ghidini. 1661.
  • De diebus decretoriis et aegrorum decubitu, 2 vols. (1661, 1665).
  • Ephemerides coelestium motuum (1661-1665).
  • Tocco di paragone (in Italian). Pavia: Giovanni Andrea Magri. 1665.
  • Tocco di paragone onde evidentemente appare che l’astrologia nelle parti concesse da S. Chiesa è vera scienza, naturale, nobile, et utile quanto la filosofia (1666), in defense of astrology as a natural science.
  • Ephemeridum caelestium motuum (in Latin). Pavia: Giovanni Ghidini. 1666.

Notes

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  1. ^ Baldini 2019.
  2. ^ Pompeo Faracovi, Ornella (2004). Nella luce degli astri: l'astrologia nella cultura del Rinascimento. Agorà. p. 243. ISBN 9788887218817.
  3. ^ a b Burns 2018, p. 268.
  4. ^ Krafft, Fritz. “astrology.” in Brill's New Pauly: Encyclopedia of the Ancient World, edited by Hubert Cancik et al., 3:985. Leiden: Brill, 2006.

Further reading

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