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Single Idea 21690

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

Full Idea

The Achilles argument is that (if the front runner keeps running) each time the pursuer reaches a spot where the pursuer has been, the pursued has moved a bit beyond.

Gist of Idea

Whenever the pursuer reaches the spot where the pursuer has been, the pursued has moved on

Source

Willard Quine (The Ways of Paradox [1961], p.03)

Book Ref

Quine,Willard: 'Ways of Paradox and other essays' [Harvard 1976], p.3


A Reaction

Quine is always wonderfully lucid, and this is the clearest simple statement of the paradox.


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]