PIERRE
80
PIETISM
Bacon in his "Opus Majus" as the only author of his
time who possessed an exact Icnowledge of perspec-
tive. According to Bacon he came from Picardy, and
the village of Maricourt is situated in the Depart-
ment of the Somme, near P^ronne. He has left a re-
markable treatise on the magnet, "Epistola Petri
Peregrini de Maricourt ad Sygerum de Foucaucourt,
militem, de magnete"; Syger de Foucaucourt was a
friend and neighbour of the author, his domain border-
ing on that of Maricourt. It is dated 8 August, 1269,
and bears the legend: Actum in castris, in obsidione
Luceriw (done in camp during the siege of Luceria),
whence we know that the author was in the army of
Charles of Anjou, who, in 1269, laid siege to the city
of Lucera or Nocera, the only detail of his life known.
The sobriquet "Pilgrim" would lead us to suppose,
in addition, that he was a crusader. The "Epistola
de magnete" is divided into two parts. The first,
a model of inductive reasoning based on definite ex-
periences correctly interpreted, sets forth the funda-
mental laws of magnetism. His part seems to have
been, not the discovery of these laws, but their pres-
entation in logical order. In the second division, less
admirable, an attempt is made to prove that with the
help of magnets it is possible to realize perpetual mo-
tion. From medieval times the work was exceedingly
popular; in 1326 Thomas Bradwardine quotes it in
his "Tractatus de proportionibus", and after his time
the masters of Oxford University make frequent use
of it. The manuscripts containing it are very numer-
ous, and it has been printed a number of times. The
first edition was issued at Augsburg, 15.58, by Achilles
Gasser. In 1572 Jean Taisner or Taisnier published
from the press of Johann Birkmann of Cologne a work
entitled "Opusculum perpetua memoria dignissimum,
de natura magnetis et ejus effectibus, Item de motu
continuo". In this celebrated piece of plagiarism
Taisnier presents, as though from his own pen, the
"Epistola de magnete" of Pierre de Maricourt and a
treatise on the fall of bodies by Gianbattista Bene-
detti. The "Epistola de magnete" was later issued
by Libri (Histoire des sciences math(5matiques en
Italic, II, Paris, 1838; note v, pp. 487-505), but this
edition was full of defects; correct editions were pub-
lished by P. D. Timoteo Bertelli (in "BuUetino di
bibliografia e di storia delle scienze matematiche e
fisiche pubblicata da B. Boncampagni", I, 1868, pp.
70-80) and G. Hellmann ("Neudrucke von Sehriften
und Karten iiber Meteorologie und Erdmagnetismus,
No. 10, Rara magnetica", Berlin, 1898). A transla-
tion into English has been made by Silvanus P.
Thompson ("Peter Peregrinus of Maricourt, Epistle
to Sygerus of Foucaucourt, Soldier, concerning the
Magnet", Chiswick Press, s. d.), also by Brother
Arnold ("The Letter of Petrus Peregrinus on the
Magnet, a. d. 1269", with introductory note by
Brother Potamian, New York, 1904).
Bektelli, Sopra Pielro Peregrino di Maricourt e la sua Epistola de Magnete in BuUetino publicata da B. Boncompagni, I (1868), 1-32; Idem, Sulla Epistola di Pietro Peregrino di Maricourt e sopra alc/uni trovati e teorie magnetiche del secolo XIII, ibid., 65-99, 319-420: Idem, Intorno a due codici Vaticani delta Epistola de magnete di Pietro Peregrino di Maricourt ed alle prime osser- vazioni delta declinazione magnetica, ibid., IV (1871), 303-31; Boncompagni. Intorno alle edizioni delta Epistola de magnete di Pietro Peregrino de Maricourt, ibid., 332-39.
Pierre Duhem. Pierre Mathieu. See Liber Septimus.
Pierron, Jean, missionary, b. at Dun-sur-Meuse, France, 28 Sept., 1631; date and place of death un- known. He entered the Jesuit novitiate at Nancy, 21 Nov., 1650, and after studying at Pont-^-Mousscin he became an instructor at Reims and Verdun; he com- pleted the curricuhim in 1665 and spent two years more as an instructor at Metz. On his arrival in Canada in June, 1667, he was sent to the Iroquoi.s mission of Sainte-Marie. In a letter written the same year he described his impressions of the country-, the
characteristics and customs of the savages, and ex-
pressed an admiration for the Iroquois language, which
reminded him of Greek. He arrived at Tionontoguen,
the principal village of the Mohawks, on 7 Oct., 1668,
where he replaced Father Fremin. These people were
one of the most flourishing of the Iroquois nations,
valiant and proud warriors, and difficult to convert.
Father Pierron made use of pictures which he painted
himself in order to make his teachings more impres-
sive, and invented a game by means of which the In-
dians learned the doctrines and devof ions of the
Church; he taught the children to read and write. He
spent one winter in Acadia to ascertain if it were pos-
sible to re-establish the missions which had been ex-
pelled in 1655, and travelled through New England,
Maryland (which at that time had a Catholic gover-
nor, Charles Calvert), and Virginia; returning to the
Iroquois, he worked among them until 1677 and went
to France in the following year. He was a man of
rare virtue, and during all his missionary career fought
against a natural repugnance to the Iroquois.
Ed. Thwaites. Jesuit Relations (Cleveland, 1896-1901); Camp- bell, Pioneer Priests of North America (New York, 1909).
J. Zevely.
Pierson, Philippe, b. at Ath, Hainaut (Belgium), 4 January, 1642; d. at Lorette, Quebec, 1688. At the age of eighteen he entered the Jesuit novitiate at Tournai, and pursued his studies at Louvain, Lille, and Douay. He was an instructor at Armentieres and Bethune before he went to Canada in 1666, where he taught grammar in the college at Quebec, and pre- sented a successful Latin play on the Passion of Our Lord. After studying theology for two years he was ordained in 1669, then worked among the Indians at Prairie de la Madeleine and Sillery. From 1673 to 1683 he did excellent work by spreading Christianity among the Hurons of the Makinac mission. In a letter from St. Ignace he described how his church increased in numbers and grew strong in faith. Later, from 1683 he was a missionary among the Sioux west of Lake Superior, and remained as such until his death.
Ed. Thwaites, Jesuit Relations (Cleveland, 1896-1901).
J. Zevely.
Pietism, a movement within the ranks of Protest- antism, originating in the reaction against the fruitless Protestant orthodoxy of the seventeenth century, and aiming at the revival of devotion and practical Chria- tianit}'. Its appearance in the German Lutheran Church, about 1670, is connected with the name of Spener. Similar movements had preceded it in the Reformed Church of the Netherlands (Gisbert Voetius, Jodocus von Lodensteyn) and on the German Lower Rhine (Gerhard Tersteegen). Among German Lutherans the mystics Valentin Weigel and Johannes Arndt ant^ the theologians Johann (jerhard, Johann Matthias Meyfart, and Theophilus Grossgebauer may be regarded as precursors of Spener.
Philipp Jakob Spener, born in 1635 at Rappoltsweiler in Alsace, had been from his earliest years, under the influence of the pious Countess Agathe von Rappolt- stein, familiar with such ascetical works as Arndt's "Sechs Bticher vom wahren Christenthum". At Geneva, whither he went as student in 1660, he was profoundly impressed by Jean de Labadie, then active as a Reformed preacher, but later a separatist fanatic. Spener foimd his first sphere of practical work at Frankfort on the Main, where he was appointed pastor and senior in 1666. His sermons, in which he em- phasizccl the necessity of a lively faith and the sanc- tification of daily life, brought him many adherents among ( Ur iiiori' serious of his hearers; but recognizing the iinpnssiliility of leading the peojilc- at large to the desireil degree of perfection, he ecineeived the ide.'i of an irrlcsiotd i/i ((t/cnii;, established in 1671) the so- called "Collegia pietatis" (whence the name Pietists),
