Concept
What the Tortoise Said to Achilles
Overview
"What the Tortoise Said to Achilles", written by Lewis Carroll in 1895 for the philosophical journal Mind, is a brief allegorical dialogue on the foundations of logic. The title alludes to one of Zeno's paradoxes of motion, in which Achilles could never overtake the tortoise in a race. In Carroll's dialogue, the tortoise challenges Achilles to use the force of logic to make him accept the conclusion of a simple deductive argument. Ultimately, Achilles fails, because the clever tortoise leads him into an infinite regression.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
Possible passages
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Zeno was concerned, as a matter of fact, with three problems, each presented by motion, but each more abstract than motion, and capable of a purely arithmetical treatment. These are the problems of the infinitesimal, the infinite, and continuity. To state clearly the difficulties involved, was to accomplish perhaps the hardest part of the philosopher's task. This was done by Zeno. From him to our own day, the finest…
Bertrand Russell, Mysticism and Logic and Other Essays
The author is tied to What the Tortoise Said to Achilles in the knowledge graph.
unchanging, indivisible; it is "immovable in the bonds of mighty chains, without beginning and without end; since coming into being and passing away have been driven afar, and true belief has cast them away." The fundamental principle of his inquiry is stated in a sentence which would not be out of place in Hegel:[30] "Thou canst not know what is not--that is impossible--nor utter it; for it is the same thing that…
Bertrand Russell, Our Knowledge of the External World as a Field for Scientific Method in Philosophy
The author is tied to What the Tortoise Said to Achilles in the knowledge graph.
But this criticism misses Zeno's point entirely. Zeno would have been perfectly willing to grant that if the tortoise can be overtaken at all, he can be overtaken in (say) twenty seconds, but he would still have insisted that he can't be overtaken at all. Leave Achilles and the tortoise out of the account altogether, he would have said--they complicate the case unnecessarily. Take any single process of change…
William James, A Pluralistic Universe
Close in meaning to What the Tortoise Said to Achilles; the term itself is not named.
Related ideas
- Law of noncontradiction
- Law of excluded middle
- Ludwig Wittgenstein
- Modus ponens
- Peter Winch
- Rule of inference
- Lewis Carroll
- Infinite regress
- Willard Van Orman Quine
- Zeno's paradoxes
- Logical consequence
- Mind (journal)
- Bertrand Russell
- Wikisource
- Tautology (logic)
- Logic
- Gödel, Escher, Bach
- Dialetheism
- Material conditional
- Conventionalism
- Douglas Hofstadter
Place in the tradition
Part of Analytic philosophy.
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