I am trying to create a better model for morality in Pathfinder. I believe my fundamental distaste is with Good and Evil being treated as equal and opposite ends of a spectrum. The idea that they are somehow 'the same, but opposite.' I would like to throw out this idea. Here's the rough draft of my new paradigm. I would like to invite your comments, advice, and criticisms!
Evil is like gravity. Evil is a powerful force pulling all things towards it. Evil does not require maintenance or care, it draws on all people and all things at varying levels.
Good is not a force, it is a code. Good is an artificial structure created by beings (humanoids, gods, others?) to benefit each other and inspire them to make the worlds better places. It requires thought, action, and effort to seek Good.
What does this mean for the rules of the game?
Lets talk divine forces first. Good has no inherent power. To receive power from Good deities, they must choose to give you that power, and can choose to deny it as well. Evil IS a power. Evil patrons can certainly reward followers with gifts, but even if a specific patron doesn't wish to give you their powers, you can simply accept more evil into yourself to access those powers. Example:
Barthak the summoner casually worships asmodeus, but does little one could call truly evil. He's your typical selfish adventurer. Asmodeus tolerates this and grants him access to Infernal Healing. Note, this is not a divine spell, but it is (evil). The power to cast this spell comes from Evil itself, and Asmodeus can access these powers easily.
One day, Barthak joins his allies on a raid against an Asmodean monastery to earn some money from the parents of some kidnapped children. The act itself is pretty selfish, but Asmodeus is not pleased. He decides that Barthak no longer deserves his power. Barthak finds his infernal healing incantation less effective, or maybe completely non-functioning. He realizes he doesn't have access to the Evil required to fuel the magic.
If he wants to continue using the incantation, he must be able to fuel it himself, no longer having Asmodus's favor. That means he must accept more Evil into himself. He could engage in murder, arson, or other despicable acts, and when he himself was Evil enough, his (evil) spells would function properly, drawing power from him now.
Essentially, the user's alignment affects access to the powers. The powers don't impact the alignment.
On the flip side, since Good is not a force, all (good) magical effects are granted by the agency of beings. There may need to be some elaboration on how divine beings impact the use of arcane (good) effects, but fundamentally, no creature can access a (good) effect without a patron's permission. Tar Baphon cannot cast Protection from Evil, or summon a Lantern Archon. Such effects are only possible through the hard work of Good beings permitting it.
Similarly, the user's alignment (and the will of the patrons) affects access to the powers
Let's talk about magical items!
I bought a wand of infernal healing, but I'm a good guy! It's not MY spell. What happens? In this case, there's 2 possibilities:
1) I use the wand as a spell trigger item with no check because it is on my spell list for one of my classes. In this case, the wand follows the same rules as the spell itself. In other words, if you don't have access to the Evil needed to fuel it (from a patron or from your own filthy, filthy soul) it fizzles.
2) I use magic device! Still possible, you can essentially try to draw upon the Evil used in creating the device (from the caster who made it, essentially) with UMD. There are already rules for this. Emulate an alignment is DC 30. Yes, this does mean that cheap arcane healing is not an option for goodly wizards at low levels.
Let's talk about non-magical fluff!
As a GM, my plan for implementing this is by adjusting how I narrate temptation and other high-stakes moral encounters. If Evil is to feel like a measurable force, I need to describe it as such. Evil characters "sinking into depravity" "giving in to destruction." The weariness of "struggling against" it for morally ambivalent characters.
In addition, characters who do adopt a code or structure of Goodness are rewarded by feeling "freed" from the corroding pull. Their prayers, meditation, or good acts may have a physical effect of relieving pain or stress, of taking "steps" in the right direction, "rising above" temptation. In other words, building an up - down dichotomy into the lexicon.
That's all I have for now! Thanks for reading.