There are six systems of philosophy, which accept the authority of the Veda: they are Nyaya, Vaisheshika, Sankhya, Yoga, Purva Mimamsa, and Uttara Mimamsa or Vedanta: Uttara Mimamsa is also called Vedanta.
Among these six systems, there is one system which is called “Yoga”. Therefore in Indian tradition, many people when you talk of yoga, they only think of this “Yoga”, which is one of the six systems of Indian philosophy. It is assumed that all that is said about yoga is contained in that book of Patanjali, which is not true. It is only one of the systems. But in that system, the end, the highest stage of yoga is called samādhi.
Here also you find the word samādhi: therefore, an impression could be created that by samādhi is meant in the Gita, the same as what is meant by samādhi in the yoga of Patanjali. But this is not true. The word samādhi is used in the Gita with a special meaning. Let us see first of all what does samādhi mean, in the Yoga of Patanjali; so that by contrast we should be able to find out, and determine the meaning of samādhi as used in the Bhagavad Gita.
It is aṣṭāṇga; there are 8 stages of Yoga in the system of Patanjali. There is yama, niyama, these are the two, then comes āsana, then comes prāṇāyāma, then pratyāhāra, dhāraṇā, dhyāna, and samādhi. These are the eight steps of that yoga. It is not my purpose to go into all these details.
The important point is that according to Patanjali’s yoga, the vibrations of consciousness, the modifications of consciousness, which are constantly occurring in our mind, in our stuff of consciousness, are to be stabilised. These vibrations, these modifications are to be stilled: yogaścittavṛttinirodhaḥ [yogasūtra 1.2]
That is the definition. “yogaś-cittavṛtti-nirodhaḥ”: nirodhaḥ means retrained, stoppage, cessation of cittavṛtti. All the modifications of consciousness (citta means stuff of consciousness), which includes everything that is in us: passions, desires, instincts, sense of myself, sense of otherness, the sense of happiness and misery, this thought or that thought, this idea or that idea, this emotion, or that emotion, everything that is a modification of consciousness, all that has to be stabilised, stilled. This is the aim of that yoga.
And when that happens, according to this yoga, there is the knowledge of the “Self”, in which there is the stillness of the being: your own being is found to be absolutely silent, and that is to be supposed the highest stage of Yoga. The cessation of the modifications of consciousness, which are occurring in our outer being, and with that cessation, the realisation of the inner Self, which is completely silent, which has to make no effort at all to be silent because its very nature is that of silence. And therefore, to remain completely silenced, that is supposed to be the highest achievement of Yoga in Patanjali.
That stage is achieved by 4 processes: pratyāhāra, dhāraṇā, dhyāna and samādhi: pratyāhāra means, you first of all determine one object, whatever object it may be. You don’t need to believe in God, or in Self, or anything, in order to pursue this Yoga. Therefore, it is irrespective of religious believe or creed or dogma. Therefore, Yoga is regarded as a science, just as a scientist requires no belief, excepting what he is to find out himself by his personal experimentation. Similarly in yoga, you select any object: it may be a tip of a lamp, it may be a tip of the nose, it may be the tip of your tongue, it may be the tip of the middle point of your eyebrows, it may be this object, or that object, or that object, or anything. You simply decide that that is the object on which you will concentrate.
In this process of concentration, the first thing that will happen is that you will be distracted to think of other things. When you decide that you will think only of this object, our consciousness, which is constantly flickering, our consciousness which is like a market place, where there is a lot of hustle and bustle going on, where all kinds of noises and sights are fleeting in a flux, and they arrest your consciousness, and your consciousness drifts, runs along all the trains of movement. That train is to be withdrawn. This is a negative movement: withdraw from all others, so that you are drawn back to this object.
It is like a child whom you want that he should read the book, and give the book in his hand and say: “Now read”. But here television is going on, here some guest is coming in, here the food is being prepared, the fourth a friend is calling, a fifth is a telephone call, and the child wants to do everything else except reading the book. He just wants to run out, and you want to drawback: this bringing the child back to the book is what is called pratyāhāra. Constantly bring back the individual to the object of concentration. When you are able to do that, then comes the next step which is called dhāraṇā: dhāraṇā is when you can concentrate on the object for quite some time: maybe for two minutes, maybe for three minutes, when your consciousness really gets stuck to it. When a child becomes interested in mathematics, falls in love with mathematics, even when he is called to take food, he does not bother about food, he is engaged in a problem solving, and wants to solve the problem, even if it is twelve o’clock at night, he doesn’t want to give it up, he is now in a state of dhāraṇā: one object on which the consciousness becomes concentrated that is the stage of dhāraṇā. When in that stage of dhāraṇā the consciousness begins to experience the object, and for quite some time, that is called dhyāna. This element of experience is very important. In the stage of dhyāna, there is a double movement: there is the movement of idea, and then, there is the movement of experience.