This is not a counter-point. A "subject" might be any concrete thing- not merely valuable things in a worldly way. A candy wrapper, a stone, a broken cup, any

This is not a counter-point. A "subject" might be any concrete thing- not merely valuable things in a worldly way. A candy wrapper, a stone, a broken cup, any thing. It can also be an abstract thing as well. What GP is saying- there must be a thing.