The problem, as is most likely psychological than metaphysical, but it still begs the eternal question of the definition of the soul.
You know the score:
Theory 1: Soul as spirit
Theory 2: Soul as conscience
Theory 2 tends to be more popular in this forum, but the definition of the soul is represented differently on the show.
What actually made me laugh is that they seemed to define the soul as the spirit on Season 5 of Ats and Spike of all people seemed to agree lol.
The rule of the thumb used to be Bangel and Angel fans were theory 1 supporters because it was remarkably convenient. Angel had more of a romantic relationship with Buffy than soulled Spike did and also all the things that Spike did for Buffy without a soul, like in Intervention etc, it wasn't soulledSpike who did those things it was the demon. Also Angel didn't torment Buffy nor kill Jenny.
So it seems counterintuitive that Spike would agree with theory 1. Just in case you're not sure what I'm talking about...
SPIKE
The thing only took over her body. Just a tip of the theological.
ANGEL
It's the soul that matters.
SPIKE
Trust us. We're kind of experts.
It's possible that Spike changed his stance due to a conversation off screen with Angel.
Spike: You know Angel, you're just jealous because I earned my soul back...
Angel: Acutally, Spike, take a look at this.
(Shows him a book on vampirism)
Spike: What??? So that means...
Angel: Yeah.
Spike: So when Buffy and I...
Angel: Sorry man.
Spike: But I went through the demon trials...
Angel: The...demon did that.
Spike: But what about when I protected Dawn by...
Angel: Wasn't you.
Spike: Oh.
Angel: Look at the bright side. At least I didn't torment Buffy all those months and it wasn't me who killed Jenny.
Spike: Oh yeah, everyone wins.
I wrote this on another forum, so out of laziness I'm going to use my copying and pasting skills, mainly because I've caned this subject.
I can't decide a) what the soul is and b) what the implications are for the slippery identity of the soul. As I quoted, from Joss, the soul is more about plot convenience than anything else, I doubt we'll get a definitive answer.
Season 4 is metaphysically messy anyway. Fred says not just that Angelus and Angel have seperate minds but that Angelus mind wasn't even there. This contradicts what Jasmine and Angelus himself says, so you have to fan wank the whole thing straight away here anyway. Wesley said that every reference to The Beast in this dimension was wiped clean, why wouldn't that include Angelus' mind was is always 'deep in'?
Masq postulates that it's possible that Angel suppresses his demon side so much that the spell didn't access it. This would work with either theory especially if Angel is doing the whole disassociative personality thing.
Either way Angel is a fragmented persona, which is why his soulless and soulled self do not find a natural synergy. Notice I say fragemented, not two personas. This also explains why he still feels guilty and rarely refers to Angelus in the third person (it was mainly in season 4 and maybe a couple of times elsewhere)
I'm slightly more on the theory 2 side but I'm still undecided. I reconcile it by saying it's like our understanding of the universe and metaphysics in real life. There are many different theories and it would appear that the vampires themselves can't tell the difference and appear to have a continued sense of consciousness. You could almost imagine a vampire reading up on vampires and saying "Huh, so I'm not the same quantitive person I was when I was human, I'm a seperate being altogther, interesting" It might explain Angel's inconsistency a little better. I think however the instinctual feeling for the vamp though is that vampire is the same person without a conscience.
While the alternative maybe true, I think this is mainly supported by those who have to kill vampires, like the WC. Ask yourself which is easier, to tell your Slayer to kill the demon who killed your mother and stole her memories or kill your mother who has many of the same feelings but is physiologically altered and lacking a conscience. The latter feels a little more icky doesn't it?
...A 'spirit' must exist. To elaborate, Buffy was said to be in heaven but her material body was clearly on earth. How can her body be on earth, when she's in heaven? Of course Btvs is cearly supporting a dualist slant here, in other word the body and the spirit are two seperate things.
Now I've deliberately used to word 'spirit' here so the our 'soul' word would remain intact. Now if we run with theory 2 (soul as conscience) we still have to deal with the spirit problem. It seems unlikely that Buffy's conscience went to heaven, that doesn't even make sense lol. It doesn't just stop there, what was being swapped between Marcus and Angel in Carpe Noctem and Buffy and Faith in This Years Girl? Also what about the existence of ghosts etc?
So we at least have to admit that spirits exist in the Verse.
No if we run with theory 1 (soul as spirit) then it's pretty intact. When they talk about the soul, it means the spirit, which we have established is very likely to exist. Any soulled vampire saying "it's me, it's me" is clearly mistaken or can't tell the difference. Angelus and Angel are seperate and so are the Spikes. It's like vampire Willow and Willow etc, things in common but different depending on the individual etc.
What about Ryan Anderson under this theory? Well the demon wasn't being literal. The word 'soulless' or without a soul can merely mean, lacking human soul qualities. Bascially there is nothing metaphysically special about Ryan, he was just a jerk, a sociopath, like Corbin Fries or the McNamaras.
Under theory 2 we have to reconcile the spirit and soul (conscience). In this theory the two exist. The spirit itself is kind of neutral or a little selfish maybe. The conscience is the pull to do what is right (put simply) and the spirit drives the body and can listen to the soul if it wishes. Under this theory, Angelus doesn't exist by himself.
He is the human spirit (personality memories, consciousness) without the soul(conscience) but with demon physiology (in it's purest form with the influence of the spirit is what we see in Pylea).
Angel is all that but with the conscience and same goes for Spike. They only difference is how they deal with it.
What does all this mean for Fred? I must admit, I'm behind on the comics but as I understand Fred's soul/spirit was destroyed when Illyria rose from her demon grave. Yet there were fragments, memories of who Fred was. Maybe these memories are powerful enough to forge almost an entity that can appear to be the 'self' or 'meness'. Vampires have this in theory 1 so it's possible these memories can form not just gateway to who Fred was but a fleeting frame in which Fred can exist, kind of like a natural synergy of person and body. The 'ghosts of the past' seep into present never leave until the body is dead. Or perhaps even if it was, Illyria has been 'contaminated' if you will with Fred's essence. Maybe this natural flow between spirit and body (an animated one like Illyria or the vamps) is what Tara may have been referencing.
In response to someone's comments about the memories of the person being dependent on the body (materialist slant, also my RL stance):
Well one thing we have to say is that we know that memories are not totally dependent on the body. We see these examples in Carpe Noctem and This Years Girl. Why would the 'LiamSoul' remember what Angelus did but Marcus wouldn't? The only way we could reconcile this is by Tara's right soul in the right body theory.
There is one thing that is clear, Angel and Spike have a feeling continued consciousness soul or no soul. Look when Angel says he's sorry about what Angelus did the Lilah. You can see him deliberately distancing himself from Angelus here, almost as if he was instinctually about to say "There is no excuse for what I did"
A lot there but I was too lazy to rethink the whole thing.