Sleep (Skt. निद्रा Nidra) is a natural, recurring state of the mind during which the physical body rests, and attention is withdrawn from the external, physical senses.

States of Sleep

Within the sleep state, the mind transitions through different sub-states of memory:

• Light Sleep: A transition state where the body is relaxed, but the senses remain partially active. It is easy to be woken up by external sounds or light.

• Dreaming State (Swapna): The state of sleep where the mind is active, creating its own rich, non-physical worlds and experiences using imagination and memory.

• Deep Sleep (Sushupti): The highly peaceful, content-free state where the active mind and senses are temporarily dissolved. It is the ground state of the universal memory.

Spiritual Significance of Sleep

For a seeker on the path of knowledge, the sleep state is deeply significant:

• The Natural State: Sleep is our most natural, non-active state of being. The yogi is said to be "always asleep" to the worldly dream of samsara.

• Yoga Nidra: When sleep is accompanied by conscious awareness, it is called Yoga Nidra. The seeker witnesses the transition across waking, dreaming, and deep sleep states, realizing that the experiencer (consciousness) is the constant background present throughout all of them.

See also

Waking state, dreaming, deep sleep, memory, experiencer, awareness.