Belief is the core principle of magic on Poneren. Everything in the world has an innate expectation of how things should work. Belief is a core concept relevant to everything, not just people, so a person's mental recognition or statement of those beliefs isn't necessary for the beliefs to exist, even for that person. Animals, plants, rocks, and the air -- everything in the world believes. Those beliefs define the laws: light, gravity, magnetism. Physics, Chemistry, Biology all exist because of this innate expectation of them, and are the mutable laws of the universe There are also immutable laws of the universe, laws which exist independent of belief: mathematics, logic, existence, and belief itself. Magic, then, is a principle by which the mutable laws of the universe can be changed: change what is believed about the universe, and the universe changes to match those beliefs. For magic to work, the magician does not need to understand how the result will be achieved. In fact, understanding too much may make it more difficult to believe in the desired result. Rather, the magician just has to believe that magic can and will produce the result desired. This initially appears to contradict the recognition that the mutable laws of the universe are held together by the belief of everything in those laws -- one person believing those laws don't work that way cannot hold back the tide of an entire universe believing that they do. The difference that allows magic to work, however, is that while everything in the universe believes the universe will continue running, very little in the universe spends any effort on believing that each specific occurrence in the universe will happen. Belief in the specific appears more powerful than belief in the general, and allows the magician's will to push through. A corollary to this then would be that belief that a specific thing in the universe will continue working should be at least as powerful as the belief that it won't, but would also have the general belief of the universe supporting it. So belief is all that's needed to cast a magical spell, but belief is also all that's needed to counter it..if the correct counter belief is held. Another difficult in changing the universe through belief is it's hard to believe the right things. If a magician believes that something can and will happen, but also believes that that effect would cause something they believe impossible to occur, their spell will be weakened or nullified. Further, because a specific belief appears more powerful, it's difficult to do magic on something being observed: it's likely that the observer, even if that is the caster themself, will inherently disbelieve things they see that they innately know cannot happen. For example, if a magician wanted a cat's fur to turn red, if they're watching the cat, they inherently expect that it's going to stay the same color as they have an inherent belief in the laws of the universe. But were the cat not under observation, it's a lot easier to believe that the cat will be red when it's seen, and not actively disbelieve that it's red at any specific point in time, allowing the magic to happen. This example also leads to another corollary: specificity of the belief is important. The magician might innately believe that a cat won't turn red, so instead believes that all non-red light will bend around it and get diffused, so only the red light gets reflected. It doesn't matter if the caster believes the cat can turn red or not, as the cat isn't. But to all appearances, it is, so it still has the same desired effect. Further, understanding enough about light to recognize that different wavelengths of light can get bent differently makes it an easier spell to cast, as it fits more into the general beliefs of the universe.