What are the Three States of Consciousness?
The three Modes of Consciousness are Waking, Dreaming, Dreamlessness.
What is the State of Waking?
It is where knowledge comes through indriyas (5 senses). It is the day time when we are in the middle of activity
When attributing itself to the Physical body, the Self is called the Pervading.
Then what is the State of Dreaming?
The dream world which is created by the dreamer and is generated by impressions of what has been seen and heard in the Waking State, Dreaming state.
When attributing itself to the Emotional body, the Self is called the Radiant.
What then is the State of Dreamlessness?
It is the deep sleep. Person waking from the deep sleep does not remember anything but experiences inner joy. This is the State of Dreamlessness.
When attributing itself to the Causal body, the Self is called the Intuitional.
Source: Tatva Bodh, Vivek Choodamani