In destiny, the term "light" is almost always used in one way: In reference to a guardian's paracausal powers, which are created by a ghost filling a corpse with light, its not just philosophical, light is a real thing that pretty much turns guardians into living weapons Similar to magicka in elder scrolls [spoiler]theres a quote from cayde saying "void light shreds vex shields" in a quest step[/spoiler]