What happens if a lich is redeemed?

[NichG]

But that presents an interesting problem, if the character can behave in a good manner, then his alignment should shift to reflect that. Since alignment is generally descriptive and not the prescriptive one. So redemption does necessitate a "good" alignment, not because the redemption results from the "good" alignment, but because the alignment results from the redemption.

If otherwise, then the alignment system is neither prescriptive, since the character can perform actions that are not in line with his alignment, or descriptive, since the character is clearly not performing actions. It's meaningless, since it isn't meaningless (game-wise or characterization-wise) we must assume that it shifts when the character in question is redeemed.

The third admissible possibility, and arguably the most likely case, is that the alignment system is descriptive of something that is not always consistent with human-scale moral philosophy. Its not meaningless, since in 90% of cases it lines up in a consistent way, but its also not a completely foolproof guide to moral decision-making because of that 10%.