Śyāmasundara: What about activities in the spiritual sky, beyond...?
Prabhupāda: Activities of the spiritual sky, that is eternal. Everything is eternal there.
Śyāmasundara: But... Isn't there motion?
Prabhupāda: Yes. Why not motion? Because there is living entities. Living entities means life force. There must be motion.
Śyāmasundara: This is his idea: all of creation means motion. There is motion everywhere.
Prabhupāda: Yes. Without motion, how there can be creation? This is called kṣobha. Nothing is created without motion.
Śyāmasundara: So he says that he wants to find some categories which define the characteristics of everything, that everything possesses these things in common.
Prabhupāda: That five elements: earth, water, fire, air... Anything you take, these things are there. And subtler things: mind, intelligence, and ego. As it is stated in the Bhagavad-gītā that these eight kinds of material elements are differentiated energy of Kṛṣṇa.