To determine if someone believes morals are merely social constructs ask, “If no humans existed, would objective moral values exist?” If they say “no” then they are moral constructivists. If they say “yes” then they believe morals exist in some objective sense independent of the human mind and human culture.
If they do exist in some objective sense independent of the human mind and human culture, what exactly is their source? God…maybe?!?!
Thinking to Believe 