We know that the greatest power is lodged in the fine, not in the coarse. We see a man take up a huge weight, we see his muscles well, and all over his body we see signs of exertion, and we think the muscles are powerful things. But is the thin thread-like things, the nerves, which bring power to the muscles; the moment one of these threads is cut off from reaching the muscles, they are not able to work at all. These tiny nerves bring the power from something finer, and that again in its turn brings it from something finer still -- thought, and so on. So, it is the fine that is really the seat of power.
Of course we can see the movements in the gross; but when fine movements take place, we cannot see them. When a gross thing moves, we catch it, and thus we naturally identify movements with things which are gross. But all the power is really in the fine. We do not see any movement in the fine, perhaps, because the movement is so intense that we cannot perceive it. But if by any science, any investigation, we are helped to get hold of these finer forces which are the cause of the expression, the expression itself will be under control.
There is a little bubble coming from the bottom of a lake; we do not see it coming all the time, we see it only when it bursts on the surface; so, we can perceive thoughts only after they develop a great deal, or after they become actions. We constantly complain that we have no control over our actions, over our thoughts. But how can we have it? If we can get control over the fine movements, if we can get hold of thought at the root, before it has become thought, before it has become action, then it would be possible for us to control the whole. Now, if there is a method by which we can analyse, investigate, understand, and finally grapple with those finer powers, the finer causes, then alone is it possible to have control over ourselves.
--Swami Vivekananda