Help me ID a resource cross reference please

Dave Gifford

I was doing a theology study on creation ex nihilio using Lexham survey of theology. One part refers to Cf.

1 Phys. iv.2   I am not sure what text that is. See attached for context

Thanks!!

MJ. Smith

Resource abbreviations are usually at the front (but occasionally at the back) of a resource. I would expect this to be a reference to Aristotle's Physics.