Your song is ending, Doctor

There's a reason Time Lords only get a certain number of Regenerations. (Yes, yes, it's been forever, where have I been? Does it matter? Moving on...) I've heard plenty of theories: the cynical, that the Council of Time Lords doles them out; the logical, that it's a biological restriction; and the intriguing, that it's actually due to some law of conservation of Vortex energy or something, and that with the rest of them locked away, the Doctor has access to all those unused Regenerations.

But I think it's simpler than that, and more interesting, especially for someone like the Doctor. Hell, he's even said it himself- he's tired, old and tired. He's getting on towards 1,000 years old, and it's been a life of near-constant chaos, danger, and intrigue. It's very much like the Heinlein-Martian idea that a city can fill with memories and need to be left behind. For other Time Lords, by the time they get to that 13th Regeneration, they've probably lived closer to four or five millennia, maybe even more; they get into a lot less trouble, overall, than he does. They've still got an enormous amount of experiences and memories, and they all get a bit tired. I think that, after everything he's seen and done, even if he had the option to take on everyone else's spare Regenerations, he wouldn't, not if he had any other choice.

Which is part of why I think they need to bring back Romana. For one thing, I think it would do the Doctor a world (or two) of good to have some family again, a friend who understands about Gallifrey and the loss of a people, an ally who can always keep up with him. Also, he's gotten a bit reckless, and I think she would rein him in expertly, keep him alive just a bit longer. But the other side of that coin is that he would have an heir, someone who can continue his work when he uses up his lives and can finally stop running. She has plenty of experience keeping up with his quick-turns, both mental and physical, and she believes in the goodness of sentient beings and in giving everyone one last chance to mend their ways. There's no one in the Universe he's more likely to trust to continue his legacy, and no one more qualified.

Lastly, one thought on a slightly different topic. Interspersed with the Eleventh Doctor stuff I've been watching, I've also gone back and watched some First Doctor, and I'm intrigued by the similarities. Anyone else with me in thinking that, before we ever met him, the Doctor was as much of a poker and a pryer and an annoyance as Amy ever found him? Granted, he was likely a bit less wacky, what with being surrounded with other Time Lords, but some of his current oddness may be senility anyway. Or at least the weight of age... *This thought inspired by Teenage Rebel by Chameleon Circuit, from the album Still Got Legs.

The Doctor and the TARDIS: Deus ex Machina

He is, as the Face of Boe has said, the lonely god, the wandering god. But he is not entirely alone. The Doctors may change, over the years, but the TARDIS remains, constancy in his chaotic life, the agent of chaos through which he creates stability.

For this is the true secret of the TARDIS: she is not broken at all, but a sentient being in symbiosis with the Doctor. He has an unparalleled urge to do good, to fix what is broken in the universe and get it all back on track, though he might not always know it, so she indulges him. He chooses a time and place to which he wants to go, and she finds the nearest point of trouble and takes him there. He may complain, and it may result in high Companion turnover, but he loves every minute of it. This is especially poignant with the Tenth Doctor, as he relearns his love of putting things right.

The Ninth Doctor needed Rose, needed someone who would just go along with him because it seemed like a good idea. He had made such terrible judgment calls, lost so much, he just needed someone who could show him the beauty and wonder of the universe again. The Tenth Doctor was a little more together, a little more willing to try his hand at changing things and interfering. Rose, however, was still trying to live as she had with Nine, bouncing around exploring more than actually changing things. This is why Martha was so good for Ten- she has such an impulse towards helping, herself, that she reawaked it in him. He began to actively seek ways to help once again.

The TARDIS, of course, always knows what the Doctor needs. She takes him to his Companions, each of whom is a perfect foil for the Doctor in some way (i.e. Rose could show him how to be happy again, Martha challenged him mentally). She helps him find what he really wants, which is a way to help. Even when all he wants is an escape, she finds a way for him to help someone, which in the end makes him feel better than a simple holiday would. More than all that, though, is an incident from the very end of Nine’s story.

***Spoilers***

The Doctor is seemingly doomed. He has sent Rose away, and locked the TARDIS so they don’t come back for him. In reverse order, Rose: saves the Doctor; leaves herself clues on how to do it in all the time/places they’ve traveled together; takes in the Time Vortex at the heart of the TARDIS (essentially becoming part of it); opens the Vortex; and finds/solves the clues. The TARDIS needs an agent, a being with arms and legs and eyes, in order to do what she wants. In this case, that means saving the Doctor, and incidentally herself, by switching her symbiosis from the Doctor to Rose for a little while. She could then bring them all back together, and fulfill Nine’s other greatest wish, to see the Daleks destroyed before his eyes.

This, by the way, is the reason Ten’s Regeneration is a little jumpy and uncertain: It is linked closely with the TARDIS herself, and she had recently expended a great deal of energy on dealing with Rose and the Daleks and all.

***End Spoiler***

In the end, though the phrase “wandering god” most definitely applies, “lonely god” does not, quite. The Doctor and his TARDIS are as close as a happily-married couple, and it is truly a Pantheon of two.

I love the sound of the TARDIS

Furthermore, I adore the direction they're taking the tenth Doctor. He's been through so much in his 900 years, and even more in the last three or four (all numbers/dates subject to interpretation- this IS a Time Lord).
**Spoilers**
I've just finished Series 3, and oh, Holy Hannah! I've gotta start with the new Master. Delicious! First of all, he has some of the same body language and thought processes as the Doctor, highlighting the fact that they're really just two sides of the same coin. The Doctor interferes because he's trying to help, and the Master interferes because he likes to meddle, and he wants to be in charge of everything. Unfortunately, the Master's newest regeneration is blatantly insane; he's a megalomaniac and a psychopath. Some of the previous regenerations were a bit crazy, but you got the sense that there was a plan. The new one just wants to rule everything, and doesn't care how he gets there. And the terrible things he does to the Doctor! Ohhh, and the way the Doctor sets it right! Gorgeous! But then the Doctor is left to deal with the fallout...
Well, you know, it was bad enough when he thought he was the only Time Lord left, but then to find out there is one other, and it's his ancient foe... How horrible and wonderful that would be! And he tries so hard to help him, to rehabilitate him, and the Master just doesn't care, doesn't want any help, doesn't even want to be around if he can't be in charge and on top of the world. Of course, if one Time Lord can hide in this way, surely others could too. For the Doctor's sake, I'm not willing to believe that there are no others anywhere. I mean, Time Lords! The whole of space/time to hide in, and the technological capacity to change their biological makeup or create a little box outside of time to hide millions of Daleks in! They're out there somewhere, in little pockets and hidey-holes, and the Doctor will find them, gather them, and rebuild his society. I'm sure of it.
The Doctor is making great strides forward anyway. Losing Rose was rough on him, but I think Martha is even more suited to be a Companion. She's sharp, quick on her feet both physically and mentally, and an excellent observer. She also challenges him more than Rose did. I do feel sorry for her that he's so busy thinking about Rose that he doesn't really see Martha for a long time, or realize her feelings for him for a lot longer. I really want him to acknowledge his own feelings more, though. He keeps so much bottled up, in order to appear strong and in control. But you can tell Martha is good for him because he's actually said the word "Gallifrey" to her, and described the place a little, neither of which he ever did with Rose. It's cheesy, but I think in some ways, Rose was an anchor, keeping him from losing himself in revenge or misery, and Martha is wings, helping him get out and explore the universe as he used to love to do.
Finally, one of my favorite parts: Captain Jack. Well, really, the whole suite of "alternative" sexualities that populate the show. (also, Jack is HOT, but that's a side issue) First there was Jack, back in the first series, who flirted with anything that was sentient and bipedal. Then he kissed Rose, and immediately the Ninth Doctor. Yum! (I have a friend who insists they were a trio, and I don't really disagree) Then, early this series, there was William Shakespeare, who flirted heavily with Martha. When the Doctor called him on it, he flirted with the Doctor, who actually somewhat responded. Then there were the old lesbians, who insisted that they were married, and clearly had that old-married-couple dynamic. And now Captain Jack has come back, but the Doctor is more impatient with his flirting ways, and less responsive. Granted, that's for complicated reasons, including the effects of Rose and the time vortex, and the fact that Jack reminds the Doctor that Rose is beyond reach, but when Martha says something about fancying the Doctor, who doesn't see her, Jack indicates that he's in the same position. I gotta say, I was really hoping Jack and the new Doctor would kiss, since that would be hella hot, and also I think good for the Doctor, but there were good story reasons why they didn't, and I'm ok with that. There were also crazy revelations about Jack and another character we've known since episode 2 or 3 (ie 9th Dr), but I'm not going to go into that yet.
I'm not sure this fits the "alternative" sexuality topic, and I'm sure it's less of a big deal in Britain, but this season had a lot of couples with a black man and a white woman. I'm not sure what to make of that, but it does intrigue me, since even now that can be a hot-button issue in the States, and no one on the show even seemed to notice, let alone care, which is cool
In summation, I'm incredibly glad it all comes back at Christmas, since I don't think I could wait til next summer for more of the gorgeous, wonderful 10th Doctor.