Nirvitarka samadhi is attained when the memory is purified, and the mind is able to see the true nature of things without obstruction.
The explanations given for the samadhis of savitarka and nirvitarka, also explain the higher states of samadhi, but in these higher states of savichara and nirvichara samadhis, the objects of meditation are more subtle.
The province of samadhi that is connected with these finer objects extends up to the formless stage of the subtle energies.
Mind is memory; it is like a computer. To be exact, it is a biocomputer. It accumulates all that is experienced, known. Through many lives, through millions of experiences, the mind gathers memory. It is a vast phenomenon. Millions and millions of memories are stored in it; it is a great storehouse.
All your past lives are stored in it. Scientists say, even in a single minute thousands of memories are being collected, continuously – without your knowing, the mind goes on functioning. Even while you are asleep, memories are being formed. Even while you are asleep: somebody cries and weeps, your senses are functioning and collecting the experience. You may not be able to recall it in the morning because you were not conscious, but in deep hypnosis it can be recalled. In deep hypnosis, everything that you have experienced ever, knowingly and unknowingly, can all be recalled – your past lives also. The simple expanse of mind is really vast. These memories are good if you can use them, but these memories are dangerous if they start using you.
A pure mind is that mind who is master of its own memories. An impure mind is that mind which is continuously impressed by the memories. When you look at a fact, you can look without interpreting it; then the consciousness is in direct touch with reality. Or you can look through the mind, through interpretations; then you are not in touch with reality. The mind is good as an instrument, but if the mind becomes an obsession and the consciousness is suppressed by the mind, then reality will also be suppressed by the mind. Then you live in a maya; then you live in illusion.
Whenever you see a fact, if you see it directly, immediately, without the mind and the memory coming in, only then is it a fact. Otherwise, it becomes an interpretation, and all interpretations are false because all interpretations are loaded by your past experience. You can only see things which are in tune with your past experience, you cannot see things which are not in tune with your past experience – and your past experience is not all. Life is bigger than your past experience. Howsoever big the mind may be, it is just a tiny part if you consider the whole existence – so small. The known is very little; the unknown is vast and infinite. When you try to know the unknown through the known then you miss the point. This is the impurity. When you try to know the unknown by the unknown inside you, then there is revelation.