Egan has a great discussion of this toward the end of Schild's Ladder:

 

“How do you carry something from here to there, and keep it the same? You move it step by step, keeping it parallel in the only way that makes sense. You climb Schild's ladder.”

Tchicaya didn't ask if the prescription could be extended beyond physics; as an answer to his fears, it was only a metaphor. But it was a metaphor filled with hope. Even as he changed, he could watch himself closely, and judge whether he was skewing the arrow of his self.

Maybe. Small errors add up. But also, I never said it wasn't a phobia. ;)