Every form of life is spiritual. Even as ice is condensed water, so matter is condensed spirit. Mineral, plant, animal, or man—each is a condensed form of the spirit.
Source: Rudolf Steiner – GA 100 – Theosophie and Rosicrucianism – Kassel, 16 June 1907
https://rsarchive.org/Lectures/GA100/English/ANS1942/19070616p01.html
The great Rudolf Steiner Quotes Site 