Intricacies of Time Travel
 

So here's what I'm trying to get my head round.

In Silence of the Library, the Doctor is called to the Library by River Song. Apparently she's met him before.

Then, in Forest of the Dead, River chooses to die over the Doctor, because that way she can still be with him in her past/his future because he survived.

But surely therefore, if the Doctor went ahead and did that thing (and died), he would never have then lived on to meet River in the first place. Since she was the one who called him to the library to begin with, The Doctor would never have went there, because he would have died before he met River, so she wouldn't have sent for him. Because River wouldn't send for him, he never would have went to the library. And cos he never would have went, he never would have died. And so he would have lived on to meet River and so on and on and on and on....

So what the hell happens then? Does the timeline reset? How can it continue in this way? It's hurting my brain trying to think of an answer to this one.

I don't think we're meant to comprehend it. I don't even think the production team comprehends it.

Um.

I'm confused. You're talking about what happened if the Doctor would have sacrificed himself, in place of River? O.o

Yeah, silly question, I know.