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SPECIAL PROBLEMS
handsj; of later and abler geometers, since it gives a method
of approximating, with any desired degree of accuracy, to the
area of a circle, and lies at the root of the method of exhaustion
as established by Eudoxus. As regards Hippocrates’s quadra
ture of lunes, we must, notwithstanding the criticism of
Aristotle charging him with a paralogism, decline to believe
that he was under any illusion as to the limits of what his
method could accomplish, or thought that he had actually
squared the circle.
The squaring of the circle.
There is presumably no problem which has exercised such
a fascination throughout the ages as that of rectifying or
squaring the circle ; and it is a curious fact that its attraction
has been no less (perhaps even greater) for the non-mathe
matician than for the mathematician. It was naturally the
kind of problem which the Greeks, of all people, would take
up with zest the moment that its difficulty was realized. The
first name connected with the problem is Anaxagoras, who
is said to have occupied himself with it when in prison. 1
The Pythagoreans claimed that it was solved in their school,
‘ as is clear from the demonstrations of Sextus the Pythagorean,
who got his method of demonstration from early tradition ’ 2 ;
but Sextus, or rather Sextius, lived in the reign of Augustus
or Tiberius, and, for the usual reasons, no value can be
attached to the statement.
The first serious attempts to solve the problem belong to
the second half of the fifth century b.c. A passage of
Aristophanes’s Birds is quoted as evidence of the popularity
of the problem at the time (414 b.c.) of its first representation.
Aristophanes introduces Meton, the astronomer and discoverer
of the Metonic cycle of 19 years, who brings with him a ruler
and compasses, and makes a certain construction ‘ in order that
your circle may become square ’. 3 This is a play upon words,
because what Meton really does is to divide a circle into four
quadrants by two diameters at right angles to one another ;
the idea is of streets radiating from the agora in the centre
1 Plutarch, De exil. 17, p. 607 F.
2 Iambi, ap. Simpl. in Categ., p. 192, 16-19 K., 64 b 11 Brandis.
3 Aristophanes, Birds 1005.