We all have a physical self, mental self, emotional self, spiritual self, ego self and many other aspects. We are indeed complex creatures, controlled by the most basic urges.
Once you have clear goals and desires, you can align the different aspects of yourself toward reaching the common goal.
Focusing on a goal sets up a powerful resonance, where the various aspects of yourself are in harmony, empowering each other to bring you to where you want to be. When your different aspects resonate with each other, you become far stronger than just the sum of your parts.