Doctor Anthony's Confusion About Moral Ontology and Moral Semantics

Theists typically maintaind that god is the ontological foundation of moral values, and without him, objective values would not exist. Theists do not maintain the iplausible sematical thesis that the word good means anything like commanded by god. God's own nature determines what is good, and his nature expresses itself toward us in the form of divine commands,. which then constitute our moral duties. Doctor anthony seems incredulous. He says, if god turned out not to exist, then slavery would be ok. There'd be nothing wrong with torture. If god does not exist, why think that objective moral values would exist? As we saw, in the absence of god, there is no