lawful what?
In response to FireLance's:
"In my view, a Lawful character would respect the law of the land, and would follow it in so far as it does not clash with the laws of his society. It is not enough to have a personal code of honour, it must be one that is accepted by society. I use the word "society" here loosely - it could be a religious order, a culture, even a criminal organization. The essence of a Lawful character is that he does not determine right and wrong by his own standards, but by the standards of the group that he identifies with."
I would agree that a lawful character would respect the law of the land, but the philosophy there after would seem to break down. Your later presumption is that the "lawfulness" of an individual would be relative to the ideas of the society that instilled those beliefs. I believe that mattcollville would be closer to describing what lawful should be when he says of a lawful character: "(he) believe(s) laws are a natural and necessary part of society."
When you begin to say "The essence of a Lawful character is that he does not determine right and wrong by his own standards..." you blur the distinction between Moral and Ethical alignment.
However, I do see why you would have reason to think along those lines, as the PHB does a very good job at avoiding a clear distinction in these two areas.
When describing "good" and "evil" they (PHB writers) list qualities or actions that we can recognize as clearly one or the other. When they later describe "lawful" they again list qualities that many people would deem favorable, or that are also "good"... and when describing "chaotic" they list both favorable qualities, and drawbacks that a "chaotic" character might have. However, and this next part is very important, they list "freedom" as a quality of a chaotic character... as though somehow the characters who have "lawful" in there alignment do not have freedom? The terms (used in each alignments description) are used ambiguously and thus cause confusion in our ideas of what alignment means. In truth, freedom should be a quality that should be listed for any thinking (read "freethinking) or willful (read "free willed") individual/character. We can see the truth in that statement by knowing this: That at every point in any one of our lives, when any character comes to a point where a decision must be made, he has precisely this, the ability to make the decision, and the freedom to choose as he wills.
Which would mean the ideas of law and chaos are simply inclinations in each individual's or each character's mind. The character can not necessarily make the "lawful" (or chaotic) choice, because there simply may not be a "lawful" (or chaotic) choice to make.
Who then has the most freedom, the lawful character who would favor order or structure in society, the chaotic character who’s inclinations would be directly opposed, or the neutral character, who is not "bound" by inclination to either.
It is difficult to say what the "lawfulness" of a character or his decisions would be if a decision he made would support the concept of and orderly or lawful society yet defies the laws of a particular society (especially if said decision is made in or directly affecting that society). The reason for this (difficulty) is that the argument can not be made in absolutes. All concepts here are relative to terms and definitions and our concepts/perceptions of them (albeit I would expect that we can all share quite similar thoughts on our definitions) Because, as in the example above, we can not say or define "what is absolutely lawful". Again, that may just be reiteration of the fact that as far as "law" and "chaos" are concerned, we have only inclinations. Those inclinations however may/would be affected by our ideas of what is "best" for society, and thus we begin to cross the line from Ethical to Moral once again, for when using the term "best" we imply that something could be better, or "more good" than another thing. (best being "most good"). "Absolute good"- that can be argued (which means what IS good would extend infinitely beyond a societal standard), however, (no matter my beliefs) it doesn’t seem to have a place in the philosophical D&D system, which uses a pantheon for its religious system, and favors the ideas of dualism (that good and evil are equal and opposite forces, taking this one step further to include equal and opposite forces embodied in the ideas of law and chaos)... but that is fine for a fantasy game. So I'll step of the soap box, and apologize if this post seems as though it belongs in some philosophy message board elsewhere on the internet.
From what is given in the description from pg 88/89 of the PHB, we see that we can expect actions from a lawful person that are expectable... another problem is, this "expectable" changes from the description of lawful good ["A lawful good character acts as a good person is expected or required to act"] (where the "expected" seems to indicate societal expectation), to lawful evil ["A lawful evil villain methodically takes what he wants within the limits of his code..."] (which now indicates that what is expectable is only the manner in which this villain has acted previously). So the villain sets his own code? How is this any different from the chaotic good character "...act(ing) as his conscience directs him"? Ironically enough, both of these characters follow there own conscious, but the villain has no compulsion to help others, where Soveliss the ranger (as used in the PHB example) does, but cares not for what others expect of him.
As far as Batman is concerned, unless this D&D philosophical system can be applied to reality (which we can very easily argue that it cannot be, given the example above), we cannot truly categorize any person existent or conceived outside the system using the same definitions (defining characteristics) given therein. However, his actions would most closely match what is described as "Rebel(?)"-Chaotic Good.
We also see here that the idea of Paladin used in D&D is just that... the D&D idea of Paladin, which has always been (since its conception) the lawful good "Crusader" (see PHB entry of "lawful good"). Thus any argument outside of that definition, stating that the Paladin "should" be anything other than what it is (in D&D) is merely subjective (subject to our own opinions, perceptions, or ideas of what we want the paladin to be), and thus all arguments pertaining thereto are equally valid... and invalid at the same time. Thus, sorry to say, each is pointless WHEN or IF trying to convince another individual (whose subjective view is not like your own) that your subjective argument or view is (absolutely) more valid or better than their own. At best, those with different opinions can merely recognize the merits of the supposed arguments that others give.
Me? I like Paladins they way they are, and truly, I see no point in trying to change what a Paladin is. As others have said, you would merely be creating a new concept, or taking a different existing one, and calling that "Paladin", when the term is already used to describe it's current concept.