We see reasons as practical expressions of an agent's identity; we expect that if they govern and direct an agent's action they must be intimate products of his or her nature and circumstances. Yet we also believe that reasons are subject to external appraisal; agents can be wrong about their reasons, and external judgements concerning those reasons exert normative pressure. These thoughts are not necessarily incompatible while they remain informal intuitions. However, they are a source of conflict in philosophical theory. I believe that the best way to satisfy the intuition that reasons are intimately ours is to follow the work of Bernard Williams, who claimed that only internal reasons exist: those which depend on the agent's motivations. In developing the case for internal reasons I attempt to show that it also goes some way to satisfying the intuition that our reasons are subject to external judgement, by allowing that we may be separated from our reasons by deliberative obstacles. Admittedly, this satisfaction is only partial. Many theories attempt to show that reasons possess normative power precisely because they are not dependent on contingent factors such as motivations. I consider several such theories, particularly those which claim that aspects of human rationality determine the reasons of all agents. I attempt to show that they fail, partly due to specific flaws in their arguments, but also more generally because they assume that reasons must be universal. The consideration of such arguments also helps develop the case for internal reasons. They reveal a common pattern of motivation and behaviour regarding reasons which is expressed in philosophical theory and in everyday talk. I argue that what is revealed is a virtue, and that, under the familiar name of reasonableness, this virtue provides the normative component our account needs, showing that the dependence of reasons on motivations is compatible with our common intuitions about reasons.