374
ZENO OF ELEA
one and all sophisms. After two thousand years of continual
refutation, these sophisms were reinstated, and made the
foundation of a mathematical renaissance, by a German
professor who probably never dreamed of any connexion
between himself and Zeno. Weierstrass, by strictly banishing
all infinitesimals, has at last shown that we live in an
unchanging world, and that the arrow, at every moment of its
flight, is truly at rest. The only point where Zeno probably
erred was in inferring (if he did infer) that, because there
is no change, the world must be in the same state at one time
as at another. This consequence by no means follows, and in
this point the German professor is more constructive than the
ingenious Greek. Weierstrass, being able to embody his
opinions in mathematics, where familiarity with truth elimi
nates the vulgar prejudices of common sense, has been able to
give to his propositions the respectable air of platitudes; and
if the result is less delightful to the lover of reason than Zeno’s
bold defiance, it is at any rate more calculated to appease the
mass of academic mankind.’ 1
Thus, while in the past the arguments of Zeno have been
treated with more or less disrespect as mere sophisms, we have
now come to the other extreme. It appears to be implied that
Zeno anticipated Weierstrass. This, I think, a calmer judge
ment must pronounce to be incredible. If the arguments of
Zeno are found to be ‘ immeasurably subtle and profound ’
because they contain ideas which Weierstrass used to create
a great mathematical theory, it does not follow that for Zeno
they meant at all the same thing as for Weierstrass. On the
contrary, it is probable that Zeno happened upon these ideas
without realizing any of the significance which Weierstrass
was destined to give them; nor shall we give Zeno any less
credit on this account.
It is time to come to the arguments themselves. It is the
four arguments on the subject of motion which are most
important from the point of view of the mathematician; but
they have points of contact with the arguments which Zeno
used to prove the non-existence of Many, in refutation of
those who attacked Parmenides’s doctrine of the One. Accord
ing to Simplicius, he showed that, if Many exist, they must
1 Bertrand Russell, The Principles of Mathematics, vol. i, 1903, pp.
347, 348.