Wednesday, 3 August 2016
time travel happens;
changing the past is possible;
there is a law against it.
In the Time Patrol timeline, future civilizations that send expeditions into the past are bound by laws enforced by the Time Patrol. In those civilizations, the Patrol operates openly whereas, in earlier periods, it had to disguise itself as firms like Dalhousie & Roberts or Engineering Studies Co. Imagine:
finding the Time Patrol in the telephone directory;
visiting the Patrol's city center offices;
maybe working in those offices in an administrative post;
applying to join the Patrol and train at its Academy in the American Oligocene.
Even as a Patrol agent, you would probably work in your own milieu without regular access to a time machine although you would holiday at places like the Pleistocene Lodge.
A time crime may or may not be similar to an ordinary crime, e.g., to assassinate the young Julius Caesar or to prevent his parents from meeting would both be a time crime - effectively the same crime: trying to change history in a particular way.
If I were in the Time Patrol timeline and were able to prevent the Holocaust, then I would feel obliged to do so. I do not believe the Patrol propaganda that I would thereby prevent my family and friends from ever having existed - although I would deprive myself of access to them.
SM Stirling's William Walker is a murderer but not a time criminal.