Resonance, Resonance II and Temporal And Causal Vortices as well as "Very Messed Up" and "Very Messed Up" II.
In the combox for "Very Messed Up," we got onto what would have been the consequences if Carl had not time traveled pastward to betray his followers. I wanted to discuss this further but found that I had already done so in some earlier posts. See the above links.
Long before people started to think about time travel, they had already become familiar with three kinds of sequences:
chronological - A happened before B;
causal - A caused B;
logical - if Socrates is a human being and if all human beings are mortal, then Socrates is mortal.
Causal is one kind of chronological.
In time travel:
familiar chronological sequences can be reversed, e.g., a man might die before he was born;
effects can precede their causes;
the question arises whether an effect preceding its cause might cause it or even prevent it;
people tend to think of different times as different places existing at the same time, thus causing endless conceptual confusion, e.g., it might be thought that, if I travel from 2016 to 1889 to prevent the birth of Hitler, then as soon as I prevent Hitler's birth, the world of 2016 changes into one in which there had never been a Hitler who was the Fuhrer of Germany.
However, there is no way that time travel can negate logical relationships, e.g., time travel cannot bring it about that, although all human beings are mortal and although Socrates is a human being, Socrates is immortal.