Full Idea
As long as we understand any time travel events to be timelessly included in the history of the world, and thus as part of the fixed continuum of events, time travel need not give rise to paradox.
Gist of Idea
Time travel is not a paradox if we include it in the eternal continuum of events
Source
Adrian Bardon (Brief History of the Philosophy of Time [2013], 6 'Time travel')
Book Reference
Bardon,Adrian: 'Brief History of the Philosophy of Time' [OUP 2013], p.131
A Reaction
This would presumably block going back and killing your own grandparent.