It is not true that thinking ceases during sleep; we think from the moment of falling asleep until we wake. Man’s thoughts are in perpetual flow in his ether-body, only he is unaware of it. Not until the moment when he returns to the body do the thoughts light up in his consciousness.
Source: Rudolf Steiner – GA 224 – The Forming of Destiny in Sleeping and Waking – Bern, April 6, 1923
Previously posted on March 14, 2019