In Doctor Who, there's no concept of multiple timelines. I remember The Doctor seeing himself after travelling back in time (viz. when Rose saved her father and in the recent episode Before The Flood). So, all events in Doctor Who happen in the same timeline.

Now, the Bootstrap Paradox. When there are concept of multiple timelines, it's not really a big problem. But, The Doctor was seen talking about the Bootstrap Paradox. Hell yeah, he even told us to Google it without giving the solution. In his own words:

So there's this man. He has a time machine. Up and down history he goes, zip zip zip zip zip, getting into scrapes.

Another thing he has is a passion for the works of Ludwig van Beethoven.

And one day he thinks, what's the point of having a time machine if you don't get to meet your heroes? So off he goes to eighteenth century Germany. But he can't find Beethoven anywhere. No one's heard of him, not even his family have any idea who the time traveller is talking about.

Beethoven literally doesn't exist. This didn't happen, by the way. I've met Beethoven. Nice chap. Very intense. Loved an arm-wrestle. No, this is called the Bootstrap Paradox. Google it. The time traveller panics.

He can't bear the thought of a world without the music of Beethoven. Luckily he'd brought all of his Beethoven sheet music for Ludwig to sign. So he copies out all the concertos, and the symphonies and he gets them published. He becomes Beethoven. And history continues with barely a feather ruffled. But my question is this. Who put those notes and phrases together? Who really composed Beethoven's Fifth?

So, my question is: Who really composed Beethoven's Fifth? The time traveller copied it and Beethoven copied it too. With the concept of multiple timelines, it's not really a big deal. In the original timeline, Beethoven composed it and when the time traveller travelled back in time, it created a new timeline and in the new timeline, nobody composed it.

But, without the concept of timeline, who really composed the Beethoven's Fifth? If something artificial exists, there must be a creator.

  • 11
    Not sure there can be an answer, that's why it is a paradox Commented Nov 12, 2015 at 17:01
  • 8
    “So, all events in Doctor Who happen in the same timeline.” Oh, ho ho ho ho ho. Commented Nov 12, 2015 at 17:28
  • "Time can be rewritten."
    – Roger
    Commented Nov 12, 2015 at 17:31
  • 3
    There have been many instances of multiple time lines. Pyramids of Mars springs to mind, where Sarah reasons Earth is OK in the future, since they just came from there, but the Doctor demonstrates to her it won't, by going to the future again and showing what it will look like if they don't solve the problem at hand first!
    – Mr Lister
    Commented Nov 12, 2015 at 17:57
  • 2
    This is more a question of philosophy than anything else. Some consider these paradoxes to be a convincing argument that backwards time travel is logically impossible. Others think it's fine as long as the past doesn't get changed, and everything forms a closed time loop. Within the Doctor Who universe, the answer to why this sort of thing is possible is probably "Why not?"
    – Ixrec
    Commented Nov 12, 2015 at 22:11

4 Answers 4


I think that's the point. The same happened in "Blink" (who first wrote the DVD easter eggs?), "The Big Bang" (How did The Doctor get out of the Pandorica?) and in the same episode you refer to ("you don't understand. When exactly did I have those ideas?"). It's the Chicken/Egg problem. Which one came first? Moffat seems to love his stable time loops. We simply can't tell the cause from the effect.

Like razethestray said, this can't really be answered.

EDIT: Did you obey the Doctor and google it? This is what Wikipedia has to say:

A causal loop is a paradox of time travel that occurs when a future event is the cause of a past event, which in turn is the cause of the future event. Both events then exist in spacetime, but their origin cannot be determined.

As I said, cause and effect can't be differentiated. That's why it's a loop.

  • 3
    "The Big Bang" also includes a moment where the Doctor consciously avoids creating (or at least, exacerbating) a new causal loop. It's a quick moment, but when Amelia shows him the note he'd written, the Doctor then writes a new note and uses the vortex manipulator to go back to give it to Amelia. If, on the other hand, he'd simply taken the already written note and gone back with it, you'd create the bootstrap paradox of "who originally wrote the note?" (Of course, you still have the issue of how he only knew what to write because he saw he'd already written it.)
    – Roger
    Commented Nov 12, 2015 at 17:31
  • 1
    There was a further practical consideration there - if the same piece of paper looped through time, possibly infinitely, it would turn to dust and fail to deliver the message.
    – Politank-Z
    Commented Nov 12, 2015 at 18:05

While The Doctor did claim that this was a hypothetical situation, it did happen on a smaller scale in several previous episodes.

  • In "The Shakespeare Code", Ten and Martha go back to meet William Shakespeare, and Martha ends up giving Shakespeare some of his most memorable quotes.
  • In "Vincent and the Doctor", when Eleven and Amy Pond go back in time to visit Vincent van Gogh, where Amy presents him with a yard full of sunflowers for him to paint (one of his famous subjects)

Unfortunately, like everything else in Doctor Who, the answer is that "time doesn't work that way". That is, the only reason the Bootstrap Paradox exists is because humans insist on seeing time as linear: it moves from A ---> B, and time travelers are moving "backwards" in time if they go from B ---> A. But as we see over and over, and as put best in "Blink", time is much more "jumbled" than that. Cause and effect simply don't happen the way we experience them.

Basically, "the universe" will rearrange time/space/cause/effect/etc in whatever way it needs to in order to be self-consistent. If Beethoven's symphonies need to exist then they will somehow exist, even if they only exist in the past because they existed in the future. If a time traveler changes the past and does something odd, the universe will reorder itself (as little as possible) to make it ok.

Martha quoted Shakespeare quoting Martha. Amy inspired van Gogh's paintings which inspired Amy. Our hypothetical time traveler became Beethoven so he could grow up loving Beethoven. There is no other explanation because there doesn't need to be, "it just is."

  • Wibbly wobbly timey wimey
    – Anthony X
    Commented Jun 15, 2016 at 1:10
  • "You named your daughter after your daughter"
    – Dragonel
    Commented Apr 5, 2022 at 16:24

I believe the fact that the Doctor said "Beethoven never existed" points to the fact that a person called Beethoven never existed.

The Time Traveller was familiar with the works of 'Beethoven', but when he travelled back in time, there was no Beethoven the person.

Once the Time Traveller copied out and wrote down the complete works of 'Beethoven', he planted them in the past, so that Beethoven's works continued-

Doctor: And history continues with barely a feather ruffled

Now, it has already been made clear to us that Beethoven never existed. Therefore, the works of Beethoven are sort of like the story of the "world snake" Ouroboros, a snake continually eating its own tail.


Reference to a similar paradox was dealt with in the Red Dwarf story "Ouroboros ", series VII episode 3, where the character Dave Lister realises that

He is his own father. When he abandons himself as a baby,

He writes 'Ouroboros' on the side of a box so that his future self could work out what to do- but, that in itself is also a bootstrap paradox. As Lister himself remembered that the words 'Ouroboros' had been written on the box, he dutifully wrote it on himself- but, whose idea was it to write the words 'Ouroboros' on the box initially?

No-one's; the use of the word 'Ouroboros', and the consequent revelation that it brings, happened because it had always happened. It was a self-creating event paradox, or a causal loop; and, as it all took place in the same time stream, this solves the Bootstrap Paradox thusly:

The works of Beethoven are a self-creating artifact: the time machine has always existed, and always travelled to that point in time to allow the Time Traveller to fabricate the works of Beethoven.

The fact that the works of 'Beethoven' existed to the Time Traveller as 'Beethoven's works', allowed them to be placed there in the past by the Time Traveller.

They existed because they had always existed, and therefore they would always exist. In a sense, they created themselves; helped along by the fact that the time traveller placed them back in time so that they would exist in their own future.


The egg came first - Marilyn Vos Savant IQ test. So, if we can answer "what came first? Chicken or egg?", surely we can find an answer for this question. I think it's simple - there is no bootstrap paradox in reality. I cant think of any instances where this paradox exists, except in fiction. So, basically, writers can establish any paradox they conceive. As viewers, we can sit back and enjoy but the bootstrap paradox cannot exist in 1 universal timeline (our reality). So, multiple timelines would have to be involved if the writer wants to make it realistic. However, i just sit back and enjoy the story even if it's not fleshed out. Shoot - I watch time travellers and zombies on tv. Ive already suspended disbelief.

  • 1
    You really are user number 55777. I thought you renamed your username. Welcome to the site.
    – user931
    Commented Nov 14, 2015 at 7:25

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