Tense, I'm curious...if you think alignment defines character, not the other way around, how do you account for ex-barbarians, ex-paladins and ex-monks? Clearly, the PHB expects that you'll have PCs who change alignment, and details the consequences there are. Is alignment something thrust upon characters, in your opinion, or something that they can change? If alignment is what they are, not HOW they are, how does it change...or do you think it never really does?
Well, I'm glad you began that as a supposition. ;-)
I don't think that alignment "defines character." I think that alignment is a fundamental part of what defines a character. By 'fundamental' I mean "serving as, or being an essential part of, a foundation or basis; basic; underlying," not "being an original or primary source" as you have taken it. (Random House Dictionary) I have made the claim that alignment is more
fundamental than action in three ways: temporally, logically, and plot-wise. This in no way implies that alignment is a unique definition of a character. I
do think that alignment is the primary source for a character's motivations, and the logical and probable actions of characters derive from their motivations.
Further, I do think that alignment can change. This also deals with DonAdam's remarks:
You can act against your current status, but your status is not fixed, so there would be no penalty or problem with it, you would merely adjust your status accordingly. In this regard, the universal principles of alignment still act as guiding principles, but it is the characters' actions that determine his particular status, or which perspective he is actually following.
But, "the characters' actions...determine his particular status" is exactly what we mean when we say "acting against alignment." A character's perspective is changing, he is changing sides and changing motivations, and this needs to be reflected in the game play, especially spell mechanics. My understanding of your claim, DonAdam, was that under a "status" approach there could be no acting against alignment. I pointed out that this only seems to be the case, because for the DM and the player to judge the change in status presumes some standard -- that standard is alignment.
So, WizarDru, I explain changing alignments as changing perspectives -- perspectives that have real game effects. But, we may be arriving at the point of the disagreement. If actions determine alignment, and alignment changes have no inherent penalty (there very well might be role-playing penalties/benefits) as DonAdam suggests, then how do we justify spells like Protection from Law? If alignment
is action (“the sum total of actions”), then we are protecting ourselves from Lawful actions, right? How does a Lawful spear thrust differ from a Chaotic spear thrust? How does a Chaotic Hammer smite with "Chaotic power?" After all, Law and Chaos are just descriptions of the actions taken by a character in the past, right? He very well might go neutral in the next five minutes. ;-) (DonAdam, I know this isn't your position.)
Seriously, I don't have to give up flexibility, alignment changes, class changes, etc. just because I choose to buy into D&D's structure of cosmic conflict. In fact, if I don't buy into it, I will need to revamp the spell system.