Humankind lives its life based on big and small pieces of thought. To maintain physical growth, the appetite is one of the requirements of the disposition. This requirement comes to our mind in the form of thought, and under the influence of this thought we are forced to eat something. Similarly, all the needs of life are bound up in this law. There is no act in our life, which does not start with thought and end with thought. When the nerves feel tired then our disposition informs us by thought that we should take a rest! And so we go to sleep.