93

164

was called the tetrad because of the figure []

Perhaps the Pythagoreans supported
themselves by book-keeping by making computations as many Italians
did at a much later day. We only know that
in a book of Boethius, who lived about A.D. 500
the Arabic figures are given and are said
to be used by the Pythagoreans. It is true that
the critics have endeavored to make it
probable, or to use their favorite expression
to “demonstrate”,— some of them that this chapter
of the book is spurious, others that
the whole of the second book of the
Geometry of Boethius in which this chapter