Complex sentence: Huemer is a moral realist and ethical intuitionist, i.e., he believes that some objective moral principles exist and that some of these moral principles that can be deduced from ethical intuitions.
Split into simpler sentences: Huemer is a moral realist, i.e., he believes that there exist objective moral principles. He is also an ethical intuitionist, i.e., he believes that these moral principles that can be deduced from ethical intuitions.