Two possible arguments against the existence of objective morality (and possible responses)

This video lecture builds off of a reading by MacKinnon & Fiala, wherein they canvas four arguments or reasons that moral skepticism or relativism are attractive. In the video I only discuss two of these reasons : (1) the existence pervasiveness, and persistence of moral disagreement and (2) the diversity of situations in which moral agents find themselves. This is part of an introductory level philosophy course, Introduction to Ethics.