Gustafson, Matt, authorTropman, Elizabeth, advisorLosonsky, Michael, committee memberChong, Edwin, committee member2016-08-182016-08-182016http://hdl.handle.net/10217/176592J.L. Mackie historically has been considered the primary defender of moral error theory. The position he defends is one of many metaethical positions an individual might hold. Moral error theory’s central thesis is that all moral claims are false or neither true nor false because of moral discourse’s commitment to some problematic thesis. Moral error theory has not always been taken seriously however. Many have responded to Mackie’s moral error theory, but they often do so in a cursory manner. Moral error theory would seem to be a historical curiosity, but not a position often adopted. In modern presentations and critiques of moral error theory the discussion often seems to be one-sided. The error theorist does not always consider the weaknesses of what he considers the best presentation of his position, and the critic does not always fully appreciate the appeal of, or fully engage with the strongest presentations of moral error theory. Often error theorists and critics of moral error theory recognize that moral error theory could be developed in a variety of manners, but limit their discussions to moral error theories which closely relate to Mackie’s original presentation of moral error theory. By developing an understanding of Mackie’s original position and new variations on his position we can see what motivates individuals to develop error theories related in some manner to Mackie’s error theory. We can also see the limits of moral error theories which build off Mackie’s error theory however. In particular, I will examine the moral error theory of Jonas Olson. Olson identifies moral discourse’s commitment to irreducible normativity as especially problematic. Identifying the limits and difficulties which plague error theories such as Olson’s should lead us to consider other manners in which one can develop moral error theories. In the end, I propose that one might be able to establish something like a moral error theory by arguing that moral beliefs are unjustified. Moral beliefs, it will be argued, are unjustified because they ultimately issue from an evolutionary source which is unreliable. Because those beliefs are unjustified, I claim that we are in error if we continue to hold those beliefs. While such a position has often been called moral skepticism, I argue that it can be seen as a sort of moral error theory.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text