My dissertation consists of two main parts. In the first part, I begin by assuming the plausibility of the libertarian thesis that agents sometimes could have done otherwise than they did given the very same history of the world. In light of this assumption, I undertake to develop a model of agency which does not employ the concept of agent-causation. My agency theory is developed in three main stages: I suggest that any agency theory must satisfy four desiderata: It must (...) adequately account for the freedom and responsibility of human agents. It must provide an adequate answer to the question of what distinguishes human actions from mere happenings. It must adequately account for the epistemological fact that human agents have an immediate and nonobservational awareness of their actions. It should have the support of a respectable philosophical tradition. I argue that agent-causation provides a theory of agency which fails adequately to satisfy these four desiderata. I claim both that human actions are uncaused exercisings by agents of their powers and that human agents typically act for reasons. I maintain that the central issue dividing agency theorists and nonagency theorists is whether reasons for performing actions cause the latter. I maintain that the sense of 'because' in 'I did x because...' is not causal in nature, but teleological. ;Having developed my model of agency, in the second part of my dissertation I investigate what are some of the paradigmatic actions human agents perform. I claim that bodily actions, such as moving an arm, are psychological in nature. Essential to my argument is the concept of a body-image. A normal agent 'feels' as if she is present in her physical arm. The way a normal agent feels is revealed in the case of a phantom limb. The subject of a phantom arm feels as if her amputated physical arm is still there and she can move while feeling armishly. I maintain that the bodily action of moving an arm is the agent's movement as a psychological arm-image of her physical arm, whether the physical arm is present or not. (shrink)