Question
Why do we see Lord Shiva under the feet of Mother Kali?
Answer
Swami Paramhansa Yogananda says in Paramhansa Yogananda, from The Essence of Self-Realization, Ways in Which God Can be Worshiped:
Kali represents Mother Nature. She is Aum, the cosmic vibration. In Aum everything exists—all matter, all energy, and the thoughts of all conscious beings. Hence, Her garland of heads, to show that She is invisibly present in all minds.
The play of life and death expresses Her activity in Nature: creation, preservation, and destruction. Hence the sword, the head, and a third hand extended, bestowing life.
“Her energy is omnipresent; hence Her streaming hair, representing energy.
Shiva, Her husband, represents God in His vibrationless state, beyond creation. Thus, He is depicted as supine.
Basically that Kali being the Shakti, creates, preserves and liberates the Universe. All this She does on behalf (because they are both One) of Lord Shiva, who is the vibrationless, Nirguna Brahman, motionless, undescribable, bliss and without attributes. Thus Shiva lays motionless and smiling in bliss, while God Kali performs the acts on His behalf.
Sri Ramakrishna Paramhansa says in The Gospel of Sri Ramakrishna – (page 271 – 2):
Whatever you perceive in the universe is the outcome of the union of Purusha and Prakriti. Take the image of Shiva and Kali.
Kali stands on the bosom of Shiva; Shiva lies under Her feet like a corpse; Kali looks at Shiva. All this denotes the union of Purusha and Prakriti.
Purusha is inactive; therefore Shiva lies on the ground like a corpse.
Prakriti performs all Her activities in conjunction with Purusha. Thus She creates, preserves, and destroys.
Thus Kali represents the vibration or Aum which is responsible for creation, preservation and liberation, while Shiva is the absolute.
This does not mean that Kali is not Nirguna or that Lord Shiva is not Saguna. This is the symbolism with which one can understand this particular depiction of the Gods. Each depiction can have multiple interpretations and multiple meanings. All Gods are One. The one manifests itself in various forms.
Upanishad statements on Truth/Brahman/GOd-realization
Ekam sat vipra bahudha vadanti (Rig Veda (1.164.46))
The Reality (Truth) is one: the wise call It by various names.
Sarvam khalvidam brahma. (Chandogya Upanishad 3.14.1)
All this is Brahman
Note: “The question: Why do we see Lord Shiva under the feet of Mother Kali?” is licensed by Stack Exchange Inc (https://hinduism.stackexchange.com/); user contributions licensed under CC BY-SA.