Quote Originally Posted by brian 333 View Post
Both can exist under D&D rules.

Conformity to a community standard is a lawful trait, as is mandating that others also conform. If such conformity is intended to benefit everyone and refusal to conform reduces the benefit available to all, then it is also good. If a member of the community flees, not only does this take away the benefit he provided to the community but it takes away the benefits the community provides him, and thus it is necessary that the confused one be brought back so he can be reeducated and learn to love his place in the community.

Freedom, even of thought, is a chaotic trait.

Paladin A, motivated by the idea that the good of the many is the highest goal, is justified in imposing conformity upon all.
These are lawful traits, yes, but you have mostly left out the "good" portion of a paladin's alignment. Valuing freedom is a chaotic trait, yes, but it is also a good trait. Good behavior that is coerced is not truly good behavior. In order to be truly good and to be rewarded as good it must be freely chosen, which requires that there also be an option to choose evil.
Respect for the dignity of sentients, part of the description of "good" in the 3.5 PHB, also requires allowing them to make their own choices.
A paladin can argue that his lawful aspect requires him to choose the good of the many over the good of the one, but his good aspect also requires that he sometimes choose the good of the one over that of the many. (Hat tip to Star Trek III)

Quote Originally Posted by Worldsong View Post
Whether paladin A can exist or not in DnD rules somewhat depends on how one interprets the rules. A DM or writer could create a scenario in which a Lawful Good deity is trying to create an army of Good to fight against Evil and to that end is telling their followers, most of which being paladins, to create an empire of Good where worship of said deity is mandatory (to ensure more soldiers for their army of Good) and all laws have to be strictly followed with draconian punishments for those who fail to do so to prevent Evil and Chaos corrupting the empire.

One person could say that this empire is actually Lawful Neutral because it's basically a system for churning out fodder for the war machine, but another could say that a Lawful Good empire doesn't require freedom of religion and that the rules are harsh but fair, with the soldiers being devoted to a Good cause (namely, the elimination of Evil).

EDIT:
And yes, such an empire could then make frivolous activities such as singing and dancing illegal and require the people living there to spend most of their time working and praying for the sake of strengthening the empire and spreading the faith. The fight against Evil requires devotion and dedication, after all.
No, no, and no. A lawful good deity understands that devotion cannot be compelled. Therefore a lawful good deity will not mandate worship, and certainly won't allow his or her followers to hand out draconian punishments for those who won't be coerced. You are describing a lawful neutral or lawful evil system that wants to call itself lawful good. Any paladin working for such a system would fall.

A good DM could still put together the scenario you describe, with the empire claiming that they do have real paladins, but there would be no true paladins on the side of this empire. The clerics would be deriving their spells from some other god, possibly even while being deluded that they were worshiping the lawful good deity.

Quote Originally Posted by hamishspence View Post
Detect Evil, at least in 3.0 to 3.5, isn't that good at fine detail. You can have a Neutral character who commits a technically evil theft (their victim could reasonably be described as "the needy" and there's no alignment change after the theft - because it requires more than one evil act to change alignment - it requires repeatedly committing Evil acts to change a character's alignment.
Like all good science, it would require strict controls and repetition to provide accurate results, but it could be done. Repeat an evil action often enough and you will shift your alignment to evil, even if it's petty theft or just lying, and that alignment shift will be detectible with detect evil.