""Power" is a central concept for politics, arguably defining the political domain as such. However, despite decades of debate across political science, sociology, and philosophy, a proper definition of power is still to be had. Existing definitions fail because they are either circular or so far removed from the ordinary meaning of "power" that they cannot credibly claim to be about the same concept. This book, employing an Arendtian approach to conceptual analysis, provides a more proper definition - power denotes the condition of having available possibilities and representing them as such - and examines its implications for the study of politics, both empirical and normative. From the vantage point of a proper definition, the book shows how, by neglecting the category of possibility, significant portions of political science and philosophy become incapable of conceptualizing power, and therefore politics. The main issue with political science is the increasingly exclusive focus on causal and probabilistic regularities; political philosophy, on the other hand, tends to prioritize various forms of a teleologically oriented normativity. Both of these approaches end up discarding possibility in favor of necessity, and are therefore unable to properly conceptualize power. Finally, bringing together the different disciplinary discourses, the book examines the conditions for the concept of power to have an actual referent, which is to say: for politics to appear in our world"--