It seems to have become a habit of mine to post meta here inspired by discussion over at elisi 's journal - in this case, it's thoughts about Spike's soulquest at the end of season 6. This is an adapted version of something I originally wrote on atbvs about a year ago.
The question is, why did Spike go on the quest to Africa? The "correct" answer - supported by comments made by Joss and the writers, not to mention Spike's own words in season 7, and on season 5 of Angel - is that he wanted his soul back all along. All that talk about the chip was deliberately misleading, leading up to what Joss called "a little something I invented called a 'plot twist'". Unfortunately, the fake-out was so good (not even James Marsters knew the real story during filming...) that the twist seems to come too much out of the blue for many people. There just seems to be nothing in Spike's dialogue leading up to the last scene in 'Grave' that would support the idea that he really did go for his soul.
What I'm going to do here, therefore, is to analyse in detail Spike's words, especially during the scene in his crypt with Clem during 'Seeing Red' when he decided to go on the quest to Africa. I'm going to try to show that despite all his talk about the chip, this wasn't really what lay behind that decision; it was only the catalyst.
SPIKE: What have I done?
We start with Spike re-living his attack on Buffy over and over again, and acting distressed and angry. Important to note: he's not angry at Buffy for stopping him raping her, as certain people have occasionally claimed (on the basis, presumably, that he was so angry at her that he decided to get the chip out to "teach her a lesson"). Otherwise he'd be re-living her kicking him away and telling him to back off, wouldn't he? No. He's shocked at what he did; he's angry at himself.
Now, I'm not going to claim that he's all surprised and shocked at the revelation that he's a (potential) rapist; he's certainly already well aware of that. Hello, vampire? In fact his next comment confirms it:
SPIKE: Why didn't I do it? What has she done to me?
No, I think Spike is shocked at the discovery that he is capable of hurting Buffy, when he swore he'd never ever do that. ("I don't hurt you") When I say 'hurting' we're talking about emotional pain, of course - physical pain is no big deal to a Slayer and a vampire, especially given their past history with each other. He went to her to apologise, perhaps even to get back together with her... and ended up doing the one thing that will almost guarantee she'll never give him another chance. No wonder he's horrified and angry at himself; he's blown it with her. And yes, that's a selfish, even an evil motivation...
...but there's the other part of it. When she kicked him away, he stopped. The old Spike wouldn't have done that... we saw in 'Fool For Love' that when a Slayer kicks him down he shouts in exultation and jumps right back into the fight. Not this time, though... he looked horror-stricken at his own actions, and slunk off in guilt and shame. Remorse is really not a feeling that vampires are accustomed to, and it can't be very pleasant to experience for the first time. Not to mention confusing.
CLEM: Oh. The Slayer, huh? Gosh. She break up with you again?
SPIKE: We were never together. Not really. She wouldn't lower herself that far. [...] Why do I feel this way?
CLEM: Love's a funny thing.
SPIKE: Is that what this is?
And now he starts talking about the chip. Which, to be sure, is the start of the misdirection. But let's see what he actually says:
SPIKE: I can feel it. Squirming inside my head.
SPIKE: The chip. Little Jiminy Cricket, gnawing bits and chunks. [...] Everything used to be so clear. Slayer. Vampire. Vampire kills Slayer, sucks her dry, picks his teeth with her bones. That's how it's always been. I've tasted the life of two Slayers. But with Buffy... This isn't the way it's supposed to be. It's the chip. Steel and wires and silicon. It won't let me be a monster. And I can't be a man. I'm nothing.
From 'The Yoko Factor':
ADAM: You feel smothered. Trapped like an animal, pure in its ferocity, unable to actualize the urges within... Clinging to one truth like a flame struggling to burn within an enclosed glass... That a beast this powerful cannot be contained. Inevitably it will break free and savage the land again... I will make you whole again. Make you savage.
DRUSILLA: I don't believe in science. All those bits and molecules no one's ever seen. I trust eyes and heart alone. And do you know what mine are singing out now? You're a killer. Born to slash and bash and bleed like beautiful poetry. No little tinkertoy ever could stop you from flowing. [...] I can see it. Little bit of plastic spiderwebbing out nasty blue shocks - and every one, is a lie. Electricity lies, Spike. It tells you you're not a bad dog. But you are. You're my bad dog and you bite.
So what can he do?
It won't let me be a monster. And I can't be a man.
That's the crucial line. And the key to it is this: the chip won't let Spike be a monster... but he doesn't want to be a monster. Not anymore. Not now that he's seen how easily he can turn on Buffy, hurt her, drive her away.
But if he doesn't want to be a monster, how can he be a man? It's impossible. Buffy might have treated him like one, on the good days ('The Gift') but he knows, now more than ever, that it's only ever a pretence. A façade.
CLEM: Hey. Come on now, Mr. Negative. You never know what's just around the corner. Things change.
SPIKE: They do... If you make them.
SPIKE: She thinks she knows me. She thinks she knows who I am. What I'm capable of. She has no idea. I wasn't always this way. It won't be easy, but I can be like I was. Before they castrated me. Before... Then she'll see who I really am.
More misdirection, perhaps. But notice the *two* 'before's... "Before they castrated me" and then a second 'before'... before what? "Before I lost my soul", perhaps?
Some people think that this is just Spike's Mwah-ha-ha speech: he's going to get himself turned back into the old unchipped Spike so he can rampage and be evil and hurt the people Buffy loves. (Remember, he already can hurt Buffy herself; the chip doesn't work on her.)
However, we should consider that Buffy knows full well what unchipped Spike was like, and what he was capable of. That wouldn't surprise her. Souled Spike - William - certainly would, however... But the irony is, of course, that Spike doesn't really know what having the soul will do to him either. I doubt he thinks it'll turn him back into an ineffectual Victorian dilletante... I'm sure he's self-confident enough to think that the essentials of the personality he constructed for himself will remain. Except he'll have a soul. And, presumably, not be Evil any more (or at least have the option). And he'll be complete, a man again, able to face Buffy as an equal. No longer a monster.
So why does Spike keep going on about the chip? (Other than, y'know, to fool the audience). Because he blames it for getting him into this situation in the first place. Before the chip, everything was black and white, and Buffy was just another Slayer to kill or be killed by. After the chip, Spike spent enough time in Buffy's company to fall in love with her. Which has brought all kinds of emotional torment to his life, so of course he's pretty angry about it.. But the chip is old news. He's had two years to get used to it. His motivation now is to solve his problem with Buffy.
Why does Spike go for his soul? Not self-preservation: he certainly doesn't give the slightest indication that he's just looking for an excuse for Buffy not to stake him. There is some evidence that he wants to make himself worthy of her, so she will no longer consider him 'beneath her'... and that's backed up by his comments in the next two episodes about "giving the bitch what she deserves." (Amusingly, One Bit Shy once suggested that he actually did think the soul would turn him back into William the simpering mummy's boy, and that this would serve Buffy right for complaining about his soullessness. It's a nice idea, but like I said above, i think Spike's ego is large enough to think he'd survive the process with his personality intact.)
Mostly, though, I think it's more self-centred. The soulquest is the only way left for him to resolve the fundamental question of who he really is. He's horrified at the monster: so he will rediscover the man. Or die trying.