Abstract: It has been suggested that there is something worrisome, puzzling, or incomprehensible about the sorts of causal loops sometimes involved in backwards time travel. This paper disentangles two distinct puzzles and evaluates whether they provide us reason to find backwards time travel incomprehensible, inexplicable, or otherwise worrisome. The paper argues that they provide no such reason.
Comment: This could be useful for an advanced UG or an MA course where Time Travel has already been taught. It's a good one to motivate the thought that time travel is metaphysically possible!