The Whoniverse is full of time travellers and "space hoppers" so if Capaldi is an actual Doctor, did anyone know about it? Surely there have been times when someone has met this incarnation of the Doctor then subsequently met an earlier version, so if it was actually part of his timeline how could he not know?

Are you following me? I'm not sure I'm following me.

You need to add some spoiler tags before you get into trouble...

Logically, that would be the case. In practice, it would be impossible to write a series this way. You could have a story or two where someone refers to meeting a version of the Doctor we've not seen yet (like Lorna at Demon's Run, or River in her first appearance), but it's not very sustainable. The character's future has to remain vague and unknowable for anything to be a threat to them.

This exactly.

There's far too much OMG MOFFATT HASN'T EXPLAINED THIS TINY PLOT POINT FROM SERIES 5!!!! and BUT THIS CONTRADICTS A THROWAWAY LINE IN SERIES 6!!!

Anyone would think that they're making it up as they go along...

It's not a Moffat problem thought. The same question applies to any Doctor.

The Brigadier met the Doctors in order because it would be confusing for the viewers and writers if he were to do any different, not because it was logically essential for him to do so.

You could say this about any doctor. Someone could easily meet the sixth doctor then encounter the first, and in fact, with river in the library, we've seen that exact type of scenario played out. Similarly though, not every doctor is going to meet someone who tells them about a future incarnation, in fact, in the big wide universe, traveling through all time and space, it's possible but more unlikely than likely.

Someone may indeed tell any doctor about a future incarnation, as river did in the library, but all that really tells the current doctor is that he will regenerate some day, which he usually already knows is an inevitability. In this case where he wasn't sure, it seems he just hadn't met anyone yet who had met 12, meaning he felt sure he would die as he was, given that he knew he'd reached his regeneration limit.

I think it is more a problem of the Moffat era actually, but only because Moffat has been the only producer / writer of Doctor Who who has really tried to tackle time travel and the conundrums that it could cause.

20th century Who rarely ventured into time paradoxes - there were small attempts in stories like Day Of The Daleks to show the effects of time travel, but nothing as bold, storytelling-wise, as say River Song meeting the Doctor totally out of order.

Regardless of one's views on Moffat's scripts and story arcs, I think that SM has created a lot of the problems of his tenure himself. By shaking up Time, by showing characters that have met the Doctor in the future, in a different order, he's leaving himself wide open to nit-picking criticism.

It's also very difficult to make such complex time travel stories comprehensible to everyone and it clearly takes an awfully long time to write such stories. This may, perhaps, be the reason that, say, Terrance Dicks or Gerry Davis didn't push for more time travel stories - they simply didn't have the, er, time to plot out the complexities and the tiny details. Which is why, for example, the Doctor and the Master would always meet in the 'right' order - it's easy to retcon this as some sort of Time Lordy thing, but it's really a making-the-overworked-script-editors-job-possible thing.

I personally think that the doctor should never encounter anyone before he has met them because all his travelling is causing the changes and should rely on his present self. It is fine if he encounters people before they have met him though.

He did meet Mel out of Order as she was actually a companion from 50 years in his future when he first met her in Trial of a Time Lord.

Admittedly the show did just skip over the 50 years including the initial meeting (from her PoV) rather than showing it.

Yeah, I'd forgotten Mel (or maybe blocked her out!). That was a right muddle though as she left with Colin at the end of ToaTL, before she'd actually met him... Didn't really work.

D'you know, I have never actually considered that before, you're absolutely right, how silly

They'd never get away with that today!

Yes, that was strange. Then again it was weird how he was being done for genocide when he hadn't actually committed the crime but Mel was there as a witness in court. The Doctor was on trial for his life but was allowed to see his own future, what if he had been executed, he would know before it happened.

There's 50 years of unseen adventures between the end of Trial and Time and the Rani.

The Doctor drops Mel back to her correct point in time (sometime after Terror of the Veroids), then spends most of the 50 years off doing other stuff before picking Mel up at the point in time she first meets him (sometime before Terror of the Veroids).

So what you are saying is, that the clips we saw in TTOAT of the Sixth Doctor and Mel, with the Vervoids, Prof. Lasksy and Mr Popplewick and so on, didn't actually happen. They were from the Sixth Doctor's future, and Mel, not having met him before, went away in the Tardis to travel with him, thus in a way, re-writing the Doctor's future, causing the Trial clips to be wiped, as though they never happened.



Edit - Peri, on the other hand, well...Sadly, that still happened, as the Doctor was picked up by the Valeyard and taken to the trial room, when she was with him.

I don't think the OP is actually breaching DS regulations. He did use a spoiler tag.

Not originally he didn't.

Which is why nate mentioned it. He wouldn't have bothered if the tags were there already. The OP edited his post to include the spoiler tags later...

Is Capaldi the first Doctor to appear in the show before the doctor actually regenerated into him? His eyes in TDOTD?

Wow - Tiggerpooh, wish you'd written the ending of ToaTL! It might have made sense. Well, sort of.
I like Corwin's theory too, but sadly that's not mentioned onscreen, so for me it must remain only a theory - like Troughton's fabled series 6B.
Basically Pull2Open has hit the nail on the head - it's all very silly, and doesn't make the slightest sense. And no matter how much retconning and fan theorising we do, the whole Trial, and especially the future sections, will always be just a bit silly.

But we can just embrace the silliness and enjoy it all?

I mean plots that have to be fan theorised right back to the first regeneration which made leaving Susan on Earth with David illogical.

For an intelligent show it really does work better if you don't think too hard

If you don't count The Watcher in the Fourth's swansong, I think so.

Brilliant! I love that.

The Doctor aging 53 years between his time with Peri and Time and the Rani is mentioned on screen and it's only logical that Mel can't have been with him for all or even most of that time.

although the final scene of TOAT suggests she did continue with him from that point

As time travel isn't possible in real life, problems like this are bound to happen when making a TV series of this nature for the length of time it's been on air.
A certain amount of suspension of disbelief has to be expected, otherwise you'll tie yourself up in knots.

isn't there an audio play story that sort of explains the whole Mel parodox. I havn't heared it but in that there are 2 sixth Doctor's roaming about at the same time in the same time period.