Sylvester once compared the Doctor with Jesus.
It's that classic tale of the little man against great odds. That, and the other classic story of someone from outside our world coming down to help us. That makes it very attractive to human beings. I don't mean to be sacrilegious, but Jesus came down from outside the world to save us and it's that kind of area. Science fiction has a quasi-religious quality to it. People who are attracted to sci-fi are often not religious in other ways but are attracted to this idea of hope for the future, so it's a kind of religion in that way.'
He's not the first person to have spotted that fans can treat the object of their love with a devotion that borders on the religious. When Michael Grade was preparing to kill-off Doctor Who he remarked that the only people who cared about it were the fans, who treated watching it as something akin to "attending High Mass."
"Fandom" is a group of people who are bound together by their love for a particular story, which they have imbued with a special significance. That could be one working definition of "religion". They hold festivals in which they re-tell and celebrate that story in various ways. They dress in peculiar clothes and wear badges with symbols and insignia on them. They venerate holy relics. They have schisms and excommunications. We have got used to people describing Doctor Who and Star Trek as examples of "cult" TV.
Above all, fans have a body of holy texts which they revere. These texts are often discussed in language which is borrowed from religion. Sherlock Holmes fans describe the forty or fifty stories which Conan-Doyle wrote as "the canon". Holmes fiction by other hands is therefore reduced to the status of "apocrypha". Star Trek fans similarly distinguish between canonical and non-canonical stories. In that case, the limits of the canon is slightly more contentious. I believe that canonicity is generally resolved by an appeal to apostolic authority. If an episode of Star Trek was written by, or under direct inspiration from, Gene Roddenbury, then it is canon. If not, then it is blotted from the book of life, or at any rate, erased from the Captain's log.(I think this means that some of Season 3 of the original series, all of the cartoons, and one of the films is excluded.) To push the analogy slightly too hard, there is a large body of Star Trek and Star Wars apocrypha – novels and comic strips and what-not – that fans regard as worth reading, but insufficient to establish any doctrine. For Star Wars fans the Clone Wars TV series is deutero-canoncial: outside the canon, but not contradicting it; the Star Wars Christmas Special is both apocryphal and heretical.
I have on at least one occasion heard this analogy used the other way round. A discussion broke out on an RPG newsgroup about the status of "Apocryphal" New Testament – the stories of Jesus' boyhood and life of Mary Magdalene. (And why not?) "Oh, they are basically just second century fan-fiction," said someone. Which is precisely what they are.
When Doctor Who was on TV, there was very little substantive extra-canonical material. There were children's "annuals" with short-stories, a Doctor Who comic strip, and a separate strip featuring the Daleks without the Doctor. If anyone ever asked what relationship this stuff had to the TV series, the answer was obviously "none at all". The comic strip featured a character called Doctor Who, for goodness sake, and his companions were a nephew and niece called something like "Topsy and Tim". The Dalek stuff was more interesting and much better drawn; it illustrated how Terry Nation envisaged his creations, and what he would have liked to have done with them if special effects budgets had allowed. But there was no sense that they shared a universe with the TV series. The comic strip had a character called the Dalek Emperor; but when the Dalek Emperor eventually appeared on the TV, he looked nothing like the comic-stip version. The comic strip said the Daleks were created by someone called Yarvelling; but when the Daleks' origins were shown on the TV, their creator turned out to be Davros. Everyone knew we were dealing with separate fictional worlds which happened to have been based on a TV show. They were not part of the canon, and they had no pretensions to be. (In fact, the "nephew" and "niece" in the comic strip might have been put in with the express purpose of signaling to the reader "This is NOT the TV Doctor, but a different one.")
But since the Gradian axe fell, there have been several bodies of work which have tried very hard to present themselves as continuations of the TV series. Virgin Books "New Adventures of Doctor Who" sequence began publication within months of the series coming to an end. For many years, Doctor Who TV stories had been written-up as novellas, at first by "Target Books", and then by Virgin. So the "New Adventures" were in effect saying "Doctor Who hasn't come to an end at all. All that has happened is that where stories used to exist in two forms, book and TV, they now exist as books alone." Given that some of the novels were being written by active Who script-writers, probably based on stories that they might have tried to get produced had the series continued, the "New Adventures" claim to be a continuation of Doctor Who was actually quite strong. They went out of their way to be consistent with the TV series, and with each other. In that sense, "canon" is less a fan's list of approved texts, more an attitude which a particular book has to itself. It was possible to read a "New Adventure" and ask "Is this real? Is this canon?" without being thought totally mad. You could hardly have asked the same question about the 1975 Doctor Who Annual.
Inevitably, because novels have more story-space than 100 minute TV shows, and because the books were catering primarily to adult "Doctor Who" enthusiasts, the character of the Doctor and the Doctor Who universe began to develop in ways that were quite unlike the TV show. A recognisable "New Adventure" genre emerged. The Doctor became darker, more meddlesome, more morally ambiguous. Ace became increasingly psychotic. Some fans bought into it in a big way. Others didn't, either because they felt that what was being established had very little to do with the TV show they loved; or simply because they didn't have time to read two 75,000 word novels a month. (The books became increasingly unintelligible as stand-alones.)
Later on the, the license reverted to the BBC themselves, and they started a series of Eighth Doctor novels. The process repeated itself. The first book was intended to be thought of as a direct sequel to the McGann TV movie: an attempt to show what would have happened in the next episode, had they made it. Scores of "BBC eighth Doctor" novels followed, with the same faith in themselves as part of the canon. The novels were consistent with each other, but also with what had gone before. But this raised the question in some fans minds: what had gone before? Did the "BBC Eighth Doctor" novels regard themselves as continuing a TV series that ended in 1987, or as following on from a long series of "New Adventure" novels. The BBC books had to decide whether the Virgin books would be regarded as "canon" or not. (The answer, as I understand it, was "maybe.")
To further complicated matters, a group calling itself "Big Finish" arrived on the scene with a license from the BBC to make "new" Doctor Who stories, featuring the original cast. This started off very much in the realms of pastiche, wheeling on, say, Peter Davison and Mark Strickson to do a Fifth Doctor / Turlough story pretty much in the style of that TV era. But then they also persuaded Paul McGann to come into the recording studio and create, to date, three "seasons" in which he plays "his" eighth Doctor character. And, of course, in the audio stories, his character develops in a way which is different again from the BBC stories. The last time I looked, the Doctor had been permenantly exiled from our universe into a "divergent" world where no-one knows what "time" means. And he's lost the TARDIS. Again, these stories go to great length to present themselves as "canon" with respect to the TV show. But how does the "Big Finish canon" regard the "BBC novels canon". Did the BBC novels "really" happen? (The answer seems to be: "our stories take place straight after the TV movie, and are continuous with each other, so from our point of view the BBC novels haven't happened. But that only means they haven't happened yet. If you want them to be "true", then you just need to have faith that the eighth Doctor evenutally returned from the divergant universe, and then had all those decades of adventures documented in the BBC books, before eventually turning into Christopher Eccleston.")
Concern about canon can get carried to insane levels. Jean-Marc Lofficier's book The Nth Doctor documents various script treatments that were rejected before the Paul McGann movie finally got made. After each section, he lovingly demonstrates how this un-made story could have been treated as consistent with the canonical stories and with the other stories which were never made! But there are reasonably good, non-fanish reasons to be at least slightly worried about "canonicity" and "continuity". If you are writing a script for a new Star Trek TV show, you presumably want to stay reasonably consistent with previous stories, and therefore, to know which previous stories to be consistent with.
But for some fans, "canon" becomes an over-riding concern. When they hear that RTD is remaking the series, their first question is not "Will it be any good?" but "Will it be canon?" with the subsidiary questions "Will we see a Paul McGann turn into Christopher Eccleston" and "When the Master appears, will they refer to all the "Master" adventures that there have been in the New Adventures, the BBC Novels and the Big Finish Audios." When they get the obvious reply "No, of course they won't, you twit; it's unlikely that RTD has heard of them, and his target audience certainly haven't", some go as far as to respon "Well, in that case, it won't be Doctor Who."
One even comes across a few extremists who think that anything released with the words "Doctor Who" on it must be regarded as having "really happened". This group got very angry about the Comic Relief skit featuring Rowan Atkinson as the Doctor. Since the comic climax to the sketch had the Doctor running through five regenerations in as many minutes, and since he is limited to twelve bodies, the skit was a revealed as an evil plot by the BBC to prevent the programme ever coming back. Once you have said something about Doctor Who, or even thought it, it becomes true.
And let's be honest. The reason that I am very excited about the new series, but can't quite be bothered to read any of the novels is that I believe that something which goes out on Saturday nights, with a theme tune and opening credits, is "real" in a way that no book (however good) can possibly be.
No new series can possibly introduce an inconsistency so extreme that fan ingenuity will not be able to explain it away. You can bet that, in a year or so, there will be a CD or a novel or a comic strip that bridge the gap between one of the Paul McGann canons, and the new Eccleston texts. Almost any explanation will do. You can say "The Peter Cushing movie took place on a parallel earth where Doctor Who was a human inventor who built a TARDIS in his back garden." You can even (I imagine someone already has) write a piece of fan-fiction in which it turns out that the Time Lords were deleted from existence by an evil deleting-time-lords-from-existence-ray, and that nature, abhorring a vacuum, caused a human Doctor to come into being because the universe needed a champion to defeat the Daleks and the Cyberman. (Eventually, the human Doctor Who confronts the War-Lord and, in the course of the struggle, discover an device that will un-delete the Time Lords. His purpose having been fulfilled, he is returned to his house a few moments before Roy Castle turns up with a box of soft-centers. You see how easy it is?) But what you can't, on the whole, do is say "Oh, the Paul McGann audio epsidoes / the Richard E Grant Cartoon / the Peter Cushing Movie ....were all just stories that some guy made up and we're going to ignore them." "Stories that some guy made up" is the one thing which Doctor Who can never be allowed to be. The basic object of faith in the fan religion is that these stories really happened.
And this is what was so weird about the presence of Sylvester McCoy in the TV movie. The movie contradicted established continuity in every way possible. It was unlike Doctor Who in detail, in spirit, in letter. It's one and only redeeming feature was Paul McGann's luminous performance. But it had Sylvester McCoy in it. We saw the Old Doctor turning into the New Doctor. And that said to us fans: this is not a new series based on Doctor Who, or a remake of Doctor Who. This is a continuation of the old series. This really happened.
That Phillip Siegal felt the need to include a regeneration scene in his Doctor Who re-launch shows that he was thinking like a fan. That RTD doesn't shows that he isn't. And that's several points in the new series favor.