The following article will feature spoilers for Doctor Who up until directly before series 8.
Doctor Who is not a show known for following its own rules very closely. This 2010 Special A Christmas Carol is perhaps the best example; featuring the Doctor’s attempts to alter a man’s past and make him a moral person. The whole concept is so superfluous and impossible, as the man’s memories are seemingly altered (yet somehow he is aware of the fact simultaneously).
While time itself is far from immutable in the universe of the Doctor, what is considered unalterable are the various “fixed points in time”. With the exception of The Waters of Mars, changing a fixed point in time is never successful, and will cause the destruction of time itself (as in The Wedding of River Song). However, although fixed points cannot be undone, one can control the circumstances of how they happened. For example, in the aforementioned Wedding of River Song the Doctor is able to cheat death by having a robotic teselecta “die” in his place. All parties who know of the Doctor’s death in Utah still record it happening-but the audience is made aware that the reality was always different than it seemed.
An identical situation is seen in The Day of the Doctor when the Doctor decides not to destroy his home planet, and the audience sees that reality always happened this way (and the audience simply never knew it). And this is my main problem with the Professor River Song. The Doctor’s wife dies the first time the Doctor meets her, in the largest library in the universe. She sacrifices herself and is killed-though the Doctor “uploads” her to the library data banks.
But here there seems to be a logical inconsistency. The Doctor loves his wife, and he has had at least 1100 years to think about her death since he saw it happen in the library. Even if we assume the worst-that River’s death is fixed point in time-wouldn’t the Doctor at least want to go to the same lengths to save River as he did to save himself? We know for a fact that River is a great actor, convincing her parents she did not know who they were throughout series 6. So if the Doctor brought River a teselecta the day before she was supposed to go the library, there is no reason the tesselecta couldn’t die in her place.
But maybe you think that that this still would not work because the teselecta’s crew of people would be killed by all the energy anyway. Fair enough, then why not use a ganger as in The Almost People? River would not even have to show up anywhere near the library since we know that Amy Pond could control her ganger from anywhere in time or space. Plus there’s probably a timey-wimey way to download the computer River’s memories so that the real River would know what that version of herself did and said in series 7.
Of course, I write this without the benefit of hindsight. Perhaps the writers of the show will write this in and bring River back from the “dead”. I for one would really enjoy it if River were a permanent part of the show, just like the TARDIS or the sonic. I just love the idea of another regenerating character on the show. Rather than waiting every three years for the Doctor to be someone new, we can have a new version of a favorite character every year and a half (as we alternate between time lords).
And before a wiseguy points this out, yes River supposedly ran out of regenerations when she healed the Doctor in Let’s Kill Hitler. But seriously? Why on earth should healing the Doctor once dispose of all the seven (at least) regenerations she still has. You could argue that River should have less regenerations because she is not a proper time lord. For writing purposes though, one could always argue that she should have more because she is not a proper time lord.
In any event, there remains the basic problem with the Doctor’s death vs. his wife’s. The Doctor once asked Clara Oswald if he was good man. If the Doctor will go to extraordinary length to save himself, but not his wife, the answer to that question is a resounding no.