One of the arguments moral relativists use to support their view that moral values are not objective is what I call the “change and diversity argument.”  It is reasoned that since moral values have changed over time (we once thought slavery was moral, but now we don’t), and moral opinions even differ from culture to culture at the present time, morality cannot be objective.

This is not a good argument for several reasons.  First and foremost, the presence of contrary opinions does not imply the absence of truth.  Just because people disagree on what is moral does not mean moral values are not objective, nor does it mean that no one is capable of possessing knowledge of moral truths.  Consider a mathematical problem posed to 10 students.  If each student provided a different answer to the same problem, would it follow that no one was right or that there is no right answer?  No.  Relativists who offer the “change and diversity” argument against objectivism are confusing moral epistemology for moral ontology.  While it may be that people can be mistaken about what is right and wrong, that no more implies that there is no moral truths than the fact that people get their sums wrong implies that there are no mathematical truths.

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