Consciousness is existence, and there are as many states of consciousness as there are states of existence. Every living being has a consciousness of its own, and the state of its consciousness changes every moment of time, as fast as the impressions which it receives change; because its consciousness is the perception of the relation it bears to things, and as this relation changes, consciousness changes its character.
If our whole attention is taken up by animal pleasure, we exist in an animal state of consciousness; if we are aware of the presence of spiritual principles, such as hope, faith, charity, justice, truth, etc., we live in our spiritual consciousness, and between these two extremes there are a great variety of gradations. Consciousness itself does not change, it only moves up and down on the scale of existence.
There is only one kind of consciousness which never changes its place because it is independent of all relation to things. It is the self-consciousness of self-existence, the realisation of the I am. It can be ignored, but once attained it cannot change, because God never changes; its change would involve non-existence or annihilation of all. He who has not attained that true self-consciousness, the realisation of the existence of his own real self does not exist. He may be highly developed physically and intellectually; nevertheless he is nothing but a compound of physical and intellectual elements and his senses of self an ever-changing illusion. He cannot die, because he has never come to life; he does not truly exist, because he does not realise his true existence. There is no one truly alive, except he who can realise his own true divine life.
Bahadur Shah Zafar