Described variously as divine activity, the dynamic aspect of Shiva, and the creative primordial vibration, spanda (“quiver” or “vibration”) is a prominent technical concept in Kashmiri (or Northern) Shaivism. It is the “throb” of the utter bliss of Ultimate Reality. It is not movement as ordinarily understood but the transcendental cause of all motion. This philosophical notion is elaborated at length in Vasugupta’s ninth-century Spanda Karika, which is often ascribed to his disciple Kallata.