“Day of the Daleks” is one of the episodes from the Jon Pertwee era that I clearly remember seeing when I was younger. It may well be the first story I encountered which featured a temporal paradox – time travel from the future to the present in an attempt to stop something from happening, only for it to turn out that the time travelers actually caused the event in the first place.
It is also the first episode I remember seeing and thinking, as the Doctor sought to escape from Daleks, “Quick, run up some stairs!”
For those interested in the show’s intersection with religion, there is material of interest. When a time traveler from the future first appears, and then disappears, the man who saw it interprets it as a ghost. And the Doctor speaks rather disdainfully of the “unimaginative nature of the military mind” when the Brigadier scoffs at talk of ghosts. Once more, the Doctor at once seems to debunk the supernatural, and to affirm its reality when understood as something explicable in scientific terms.The episode also explores some very serious ethical questions. The time travelers come from a future where ongoing human war (“Humans are always squabbling over something”) left Earth vulnerable, and the Daleks took over. And so they have come back to kill the person they believe was responsible for causing that state of war. They ask whether killing one man to save millions is still murder.
The Doctor says at one point, “Changing history is a very fanatical idea.” And that applies not only to trying to time travel to the past and rewrite it. Trying to change what history will be from a future perspective is also rather fanatical. (There is a great SMBC cartoon about trying to change history through time travel which is relevant to this topic).
The figure of the controller is also an interesting one to look at in relation to moral questions. Is it better to be a quisling and help save lives, or to fight? It can be easy to treat the answer to such a question as simple and straightforward, but in practice things are more complex.
If you’ve seen the episode, what did you think of it? And what’s the first story you read or watched that features a temporal paradox?