Nick Smith (Sydney): The Grandfather Paradox: You're Doing it Wrong
The most important objection to the logical possibility of backwards time travel (btt) is the so-called Grandfather Paradox (GP). Lewis presented a solution to GP in 1976. On the one hand, it has been widely accepted that Lewis showed that GP does not threaten the logical possibility of btt. On the other hand, there have been numerous arguments to the effect that Lewis's solution generates further problems: that Lewis saves the *possibility* of btt at the price of rendering btt extremely *improbable* or mysteriously *inexplicable*. I have addressed the improbability worry elsewhere. Here I address the inexplicability worry. I first argue that the worry is misplaced: there need be nothing mysteriously inexplicable about time travel scenarios. I then argue that in light of this solution to the inexplicability worry, we can see a better way of responding to the original GP. This response -- unlike Lewis's -- does not provoke further worries about improbability or inexplicability.