In this thesis I try to develop a partial theory of normativity and justification. In the first part of the thesis I try to explore the possibility of what I call ’normative pluralism’, a position which holds that there exists a plurality of fundamental normative concepts. I argue that this plurality arises because all oughts and reasons are necessarily relative to some normative standard, and there exists a plurality of these normative standards. Examples of such standards are morality and prudence, but there could be many more. Each of these standards is genuinely normative and consists of criteria that contribute to determine what one ought. These standards are also held to be incommensurable. Throughout the thesis I also argue against the common monistic view of normativity which holds that there is only one fundamental normative concept (usually the concept of ’ought-all-things-considered’). This view is represented by the writings of John Broome, Ralph Wedgwood, and Niko Kolodny. I argue that this view is forced to make some difficult trade-offs with regard to the question of what considerations are normative, and that it therefore has unintuitive consequences. Against the concern over how well the theory I defend would encompass practical reasoning, I try to work out an alternative conception of practical reasoning based on an account given by Joseph Raz.
In the last part of the thesis I examine normative pluralism’s implications for justification. I argue that there are many types of justification, and that the standard of morality does not need some extramoral justification, as externalists about moral reasons believe. This means that moral norms are internally justified, and that the question of ‘why follow moral norms?’ should be answered on specifically moral grounds.