more from this thinker     |     more from this text


Single Idea 7557

[filed under theme 5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / a. Achilles paradox ]

Full Idea

Presumably Zeno appealed to the axiom that the whole has more terms than the parts; so if Achilles were to overtake the tortoise, he would have been in more places than the tortoise, which he can't be; but the conclusion is absurd, so reject the axiom.

Gist of Idea

To solve Zeno's paradox, reject the axiom that the whole has more terms than the parts

Source

Bertrand Russell (Mathematics and the Metaphysicians [1901], p.89)

Book Ref

Russell,Bertrand: 'Mysticism and Logic' [Unwin 1989], p.89


A Reaction

The point is that the axiom is normally acceptable (a statue contains more particles than the arm of the statue), but it breaks down when discussing infinity (Idea 7556). Modern theories of infinity are needed to solve Zeno's Paradoxes.

Related Idea

Idea 7556 A collection is infinite if you can remove some terms without diminishing its number [Russell]


The 9 ideas with the same theme [problem when analysing a pursuit race]:

The fast runner must always reach the point from which the slower runner started [Zeno of Elea, by Aristotle]
We don't have time for infinite quantity, but we do for infinite divisibility, because time is also divisible [Aristotle on Zeno of Elea]
The tortoise won't win, because infinite instants don't compose an infinitely long time [Russell]
To solve Zeno's paradox, reject the axiom that the whole has more terms than the parts [Russell]
The Achilles Paradox concerns the one-one correlation of infinite classes [Russell]
Whenever the pursuer reaches the spot where the pursuer has been, the pursued has moved on [Quine]
Space and time are atomic in the arrow, and divisible in the tortoise [Devlin]
An infinite series of tasks can't be completed because it has no last member [Lowe]
Zeno assumes collecting an infinity of things makes an infinite thing [Rovelli]