Elementary arithmetic, with brief notices of its history... by Robert Potts.

INTRODOUCTION.

17

knowledge. The authority I mean here is that which many have
violently usurped of their own self-will and with the lust of power,
and to which the ignorant vulgar have yielded, to their own ruin, by
the just judgment of God (in pernicionem propriam judicio Dei
iusto). Now, where these obstructions exist, no reason can move, no
judge decide, no law bind; right has no place, the dictates of nature
no force; vice flourishes, virtue fades; truth expires, and falsehood
rules supreme. Even if the first three can be got over by some great
effort of reason, the fourth remains. Men presume to teach before
they have learned, and fall into so many errors both in science and.
common life, that we see a thousand falsehoods for one truth. And
this being the case, we must examine most strictly the opinions of
our predecessors, that we may add what is lacking in them, and
correct what is erroneous, but with all modesty and allowance. WVe
must with all our strength prefer reason to custom, and the judgments
of the wise and good to the opinions of the vulgar; and we must not
use the triple argument-it is established-it is customary-it is
common,-and therefore it is to be retained, whether in opposition to,
or in accordance with the dictates of truth and reason." The man
who held and expressed such opinions was a very dangerous person;
and accordingly he was imprisoned, his works forbidden to be read,
and his lectures prohibited in the University of Oxford. The learned.
monk, while engaged in his inquiries into the works of nature, and
in his experiments in alchemy, was seriously believed to have
practised magic, and to have had converse with evil spirits. So
gross in that age was the ignorance of the clergy that even Anthony
A Wood, the Oxford antiquary, who had no prejudices against the
clergy, has stated with respect to their knowledge of geometry, that
"they knew no property of the circle but that of keeping out
the devil, and thought that the angles of a triangle would wound
religion."
Thomas Bradwardine was born at Hatfield, in Sussex, about the
close of the thirteenth century, and received his education at Merton
College, Oxford. He was distinguished both as a divine and as a
mathematician. He constantly attended Edward the Third during his
wars in France, and was most probably present at the battle of
Cressy in 1346. His works, "De Arithmetica Practica," and "De
Proportionibus," were printed at Paris, the former in 1502, and the
latter in 1495. He died in 1349, forty days after his consecration to
the see of Canterbury.
Mabillon, in his work entitled "D e Re Diplomatica," after the
examination of above 6000 documents, writes that he found no authentic date in Arabic figures earlier than that of 1355, and that data
in the handwriting of Petrarch.1
Geoffrey Chaucer, the poet, who died A.D. 1400, calls, in one of his
poems, the Arabic numerals "the figures newe." He had visited
Italy, where he would have learned that the science of number was
I In the "Journal of the Archmological Institute," vol. vii., p. 85, is a fac-simile
of a date in a public document of 19 Edw. II., 1325 A.D., in which the date of the
year is expressed in one part in Roman numerals, and in another in Arabic. The,
document is a warrant from Hugh le Despenser to Bonefez de Peruche and his
partners, merchants of a company, to pay forty pounds, dated February 4, 19 Edw.
II. In a different hand on the dorse, is a memorandum of the payment, written by
one of the Italian merchants to whom the warrant was addressed.