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What three claims were involved in Diodorus Cronus’s Master Argument?
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History of logic
Zeno's paradox, illustrated by Achilles' racing a tortoise.
The Master Argument, originated by the Megarian philosopher Diodorus Cronus, posits that the following three propositions are jointly inconsistent, meaning at least one must be false:12
- Everything true about the past is now necessary (the past is settled and unchangeable).
- The impossible does not follow from the possible.
- There is something that is possible, and yet neither is nor will be true (there are unrealized possibilities).
Diodorus was unwilling to reject the first two claims, leading him to reject the third. Consequently, he argued that whatever is possible must be realized either in the present or in the future, effectively denying the existence of possibilities that never come to pass.12