Yoga is practical psychology. When you are studying yoga you have to remember that you are basically studying psychology and you are also going one step further to applied psychology. You go into the depth of the human mind, human consciousness in search of practical application. And this search is methodical. You remember we had defined yoga as a methodized effort. It is a methodical study and therefore it is a scientific study. You are not required to have any basic dogma. There is no dogma in Yoga. There is no preconceived idea. Just as you make a study of steam in physics: how you can produce steam, how steam works. You may see a kettle of water on a stove which is burning and you suddenly see the lid being thrown open because steam is a force and by the pressure of the force the lid is opened up. It is the natural tendency of steam: it always pushes. Having seen this you may then apply it. If you want to push anything you know that steam can be produced and can push. We all have seen railway trains and some railway trains are moving by virtue of steam engines. Have you see a steam engine? In steam engines you have plenty of water, a lot of coal which is ignited and becomes the fuel with which water is heated to such an extent that it can push. A small illustration of a kettle with steam pushing on the lid can be applied on a large scale and can produce such a big effect that huge trains can be moved and pushed by the power of steam. This is the result of the application of this knowledge of steam — that steam can be produced and can be used to push big loads of weight in the direction that you want. You can choose what direction you want. Similarly you discover that consciousness is like steam. It is not very evident, when you think you don’t feel any kind of movement or of pushing. Because normally our thinking is very limited — like a limited amount of water, producing a limited amount of steam which can push only a little thing. But if you can produce a huge amount of steam then big things can be pushed forward. Similarly Yoga has discovered that there is consciousness and consciousness can be made to move, it is a power. And with the result of this power which is generated you can move forward. You can generate this power by methodize effort. You make an effort but in a methodized manner and as a result you can produce a tremendous amount of power of consciousness and with that power if you want you can move mountains. All this by the power of consciousness. Like electricity. Electricity is also a force. The method by which you can produce steam is not the same method by which you can produce electricity. There are other methods. Normally we see electricity as lightning in the sky when the clouds collide and suddenly you find a streak of electricity, a light flashing out. If you study how that lightning is produced, you can create methods by which whenever you want you can produce electricity. If you study how electricity is produced suddenly in nature you can then apply it and then electricity is produced. Similarly in case of yoga you can produce electricity in consciousness. Actually electricity exists in our body. You know our nerves are all electric nerves. Normally we don’t see electricity working in our body but our body is very electrical. Quite naturally there is electric force running all the time. Sometime some people become paralyzed and you ask the question: What is paralysis? It is nothing but the stoppage of the electric current in the body. It is basically the stoppage of the electric force which is normal. All our organs are moving because of electric force. And often this electric force runs automatically. When you touch an object an electric force is produced. And as a result there are reactions which are also generated by electric force. It is found that, if you know psychology, if you know what is consciousness, you can learn when consciousness can produce the electricity or a greater electricity, greater force than even electricity. What are the methods which can turn the consciousness in us which is simply like a small stream into an ocean? How do you do that? The knowledge of consciousness and the method by which this consciousness can be developed methodically that is the shastra of Yoga. Shastra means science. It is this subject with which we are dealing now.
As Sri Aurobindo says, that shastra is already in us. But we have forgotten it. It is potentially present in us and we can open it up. But as Sri Aurobindo says, sometimes you need a word to open up. It is also part of shastra. A mere word can unseal the blockage of consciousness. In fact this is happening to us all the time. Whenever you hear something, there is a vibration, our consciousness is affected. Many people, knowing the effect of words on consciousness have developed the art of advertisement. You see so many advertisement all over the world — huge letters, short sentences — and they are relayed onto our mind. And advertisers know that if publicity, advertisement is successful, thousands and millions of customers will run to the shops. It is a power. It is a very small utilisation of the knowledge of consciousness. They know that words can move the consciousness. And if that word is relayed at a particular place it is very important. Put in a place where they can reach a larger number of people and also the way in which the words are used they can be made to move millions of people. These are ordinary uses of the knowledge of consciousness.