Law is: order, consistency, tradition, self-discipline, respect for authority, honour, planning, forethought.
However, it is also: inflexibility, close-mindedness, intolerance, judgment, inability to adapt, despotism.
Chaos is: disorder, creativity, spontaneity, individual power, flexibility, adaptability, tolerance.
However, it is also: unfaithful, untrustworthy, recklessness, resentment toward legitimate authority, anarchy.
Neutral is: Someone who believes extremes (at either end) cause issues.
However, it is also: Someone without the moral fibre to commit.
It might also be: A beast - without the mental capacity to choose.
Lawful people believe that a society must be structured and defined, otherwise it falls apart. Chaotic people believe a society must be open and free, otherwise it falls apart. Both are, to some extent, right.
Good is: The needs of the many outweigh my needs. I will go out of my way and impoverish myself to help others.
Neutral is: My needs generally outweigh the needs of the many. However, I'm not going to screw others over to get what I want, but on the other hand I'm not going to screw myself over to give others what they want either.
Evil is: I don't care about the needs of the many. It's all about me. I might just ignore them or I might go out of my way to screw them over.
AngryGM has an interesting take on this. He says that motivation has nothing at all to do with good or evil. Evil is all about what line you'll cross over to achieve your motivation.