I'm having the issue where I can see Fe in myself, but I don't see either Si or Ni. There must be some reason why Fe must be paired with introverted perception, other than "It's the rules". There must be a way they work together as a whole, like Fe being the wheels and Si or Ni being the axle. One cannot move without the other. It's like needing both length and width, or both time and space, in order for things to happen. So how does Fe work with Si and Ni? Does it work differently depending on which one is dominant and which is the auxiliary?