"Begin at the beginning... and go on till you come to the end: then stop."
- Lewis Carroll, Alice's Adventures in Wonderland
As opposed to (in no particular order): starting in the middle, stopping after the end, starting before the beginning, or stopping before the beginning.
There is some implication here about the identity of indiscernables, which may require a relativistic adjustment per Einstein: I'm thinking of trains and flashlights, and whether anyone really sees the same object.
Is the PSR subject to relativity also? In the sense that varied accounts of the perceptual order of events would imply different chains of causation to different observers?