...to be in process of continual change, of motion

Question

Far from being dead, lifeless, inert, it is the very nature of matter to be in process of continual change, of motion. Once we realise this, then there is an end of appeal to the "initial impulse". Motion, like matter, never had a beginning.

[Materialism and the Dialectical Method - Maurice Cornforth] So, should we understand the bold text as:

1. it is the very nature of matter to be in process of continual change and to be in process of motion.

or

2. it is the very nature of matter to be in process of continual change, that is, in process of motion?

Answer 1

Things like this can be easily understood when the two parts have words in common, and fortunately in this case they do:

in process of continual change,
           of motion.

The "of" at the beginning of the final phrase matches the "of" at the beginning of the preceding phrase.

Separated as they are by a comma, the second phrase is simply a different way of saying the same thing as the first.

(The grammatical term for this is apposition.)