Our Mind
Thought is the implicit impulse in everything. And what do we mean by this? Just this: Your every act - every conscious act - is based on a thought.
Your dominant thoughts influence your dominant actions. In the mastery of our own brains we have total control, or should have it, and if at any time we don't, then there is a technique by which we can gain control, and in the mastery of the brain become thorough masters.
To get to the real substance of the matter, let us look at this for a minute. For if thought is forever the parent of our acts, habits, character, life, then it is essential that we know fully how to master our thoughts.