After pratyahar, when you have started coming back nearer home, coming nearer your innermost core, you are just at the gate of your own being. Pranayam brings you near the gate; pranayam is the bridge from the out to the in. Pratyahar, returning, is the gate, and then is the possibility of dharana, concentration. Now you can become capable of bringing your mind to one object. First, you gave direction to your body; first, you gave direction to your life energy -- now you give direction to your consciousness. Now the consciousness cannot be allowed to go anywhere and everywhere. Now it has to be brought to a single goal. This goal is concentration, dharana: you fix your consciousness on one point.
When consciousness is fixed on one point, thoughts cease, because thoughts are possible only when your consciousness goes on wavering -- from here to there, from there to somewhere else. When your consciousness is continuously jumping like a monkey, then there are many thoughts and your whole mind is just filled with crowds -- a marketplace. Now there is a possibility -- after pranayam, there is a possibility of pratyahar -- you can concentrate on one point.
If you can concentrate on one point, then comes the possibility of dhyan. In concentration you bring your mind to one point. In dhyan you drop that point also. Now you are totally centered, nowhere-going -- because if you are going anywhere it is always going out. Even a single thought in concentration is something outside you -- object exists; you are not alone, there are two. Even in concentration there are two: the object and you. After concentration the object has to be dropped.
All the temples lead you only up to concentration. They cannot lead you beyond it because all the temples have an object in them: the image of God is an object to concentrate on. All the temples lead you only up to dharana, concentration. That's why the higher a religion goes, the temple and the image disappear. They have to disappear. The temple should be absolutely empty, so that only you are there, and nobody else, no object: just pure subjectivity.
Dhyan is pure subjectivity, contemplation -- not contemplating "something," because if you are contemplating something it is concentration. In English there are no better words. Concentration means something is there to concentrate upon. Dhyan is meditation: nothing is there, everything dropped, but you are in an intense state of awareness. The object has dropped, but the subject has not fallen into sleep. Deeply concentrated, without any object, centered -- but still the feeling of "I" will persist. It will hover. The object has fallen, but the subject is still there. You still feel you are.
This is not ego. In Sanskrit we have two words, ahankar and asmita. Ahankar means "I am." And asmita means 'am.' Just "amness" -- no ego exists, just the shadow is left. You still feel, somehow, you are. It is not a thought, because if it is a thought, that "I am," it is an ego. In meditation the ego has disappeared completely; but an amness, a shadowlike phenomenon, just a feeling, hovers around you -- just a morning mist-like thing that hovers around you.