ANAXAGORAS 
173 
categories and called ‘ air ’. The aether took the outer, the 
air the inner place. From the air were next separated clouds, 
water, earth and stones. The dense, the moist, the dark and 
cold, and all the heaviest things, collected in the centre as the 
result of the circular motion, and it was from these elements 
when consolidated that the earth was formed; but after this, 
in consequence of the violence of the whirling motion, the 
surrounding fiery aether tore stones away from the earth and 
kindled them into stars. Taking this in conjunction with 
the remark that stones ‘ rush outwards more than water ’, 
we see that Anaxagoras conceived the idea of a centrifugal 
force as well as that of concentration brought about by the 
motion of the vortex, and that he assumed a series of pro 
jections or ‘ whirlings-off” of precisely the same kind as the 
theory of Kant and Laplace assumed for the formation of 
the solar system. At the same time he held that one of the 
heavenly bodies might break away and fall (this may account 
for the story that he prophesied the fall of the meteoric stone 
at Aegospotami in 468/7 b.c.), a centripetal tendency being 
here recognized. 
In mathematics we are told that Anaxagoras ‘ while in 
prison wrote (or drew, eypafe) the squaring of the circle’. 1 
But we have no means of judging what this amounted to. 
Rudio translates eypa0e as c zeichnete ’, ‘ drew ’, observing that 
he probably knew the Egyptian rule for squaring, and simply 
drew on the sand a square as nearly as he could equal to the 
area of a circle. 2 It is clear to me that this cannot be right, 
but that the word means ‘ wrote upon ’ in the sense that he 
tried to work out theoretically the problem in question. For 
the same word occurs (in the passive.) in the extract from 
Eudemus about Hippocrates: ‘ The squarings of the lunes . . . 
were first written (or proved) by Hippocrates and were found 
to be correctly expounded ’, 3 where the context shows that 
kypd(f)r]aav cannot merely mean ‘were drawn ’. Besides, 
TeTpaycovurgos, squaring, is a process or operation, and you 
cannot, properly speaking, ‘draw’ a process, though you can 
‘ describe ’ it or prove its correctness. 
1 Plutarch, De exit, 17, 607 f. 
2 Rudio, Der Bericht des Simplicius uber die Quadraturen des Antiphon 
und HippoJcrates, 1907, p. 92, 93. 
3 Simpl, in Phys.pp. 61. 1-8 Diels ; Rudio, op. eit., pp, 46. 22-48. 4.