Ted Sider writes that "many are impressed with the utility of possible worlds in linguistics and philosophy", and this is true, in particular, of those with an interest in modal logic. However, in the midst of the marvelous milieu brought on by the development of possible world semantics, some have stopped to ask just what it is that possible worlds are. They certainly seem useful, and we seem to understand how to use them and talk about them, but what precisely is it that we're talking about when we talk of possible worlds? In this thesis, I will attempt to outline the most significant and well-recognized view in this debate: that of David Lewis. Through my discussion of him, I will find occasion to discuss some alternative views that have arisen. After finishing my presentation of Lewis, I will discuss where people have begun to take this debate and address the question of whether progress can be made towards a substantive answer. In Chapter I, I begin by presenting the motivation of the question of possible worlds found in the study of modal logic. I then present the major approaches taken to answering the questions that were raised, leading into my discussion of David Lewis's famous and robust account. I present key features of Lewis's view and then move into his criticisms of the other major responses. This much should suffice as a relatively thorough treatment of the answers that have come before. In Chapter II, I discuss the current state of the debate. I begin by mentioning several problems that can be spotted in Lewis's views in particular. I then move to Menzel's account, which tries to answer the question of possible worlds from a new angle, jettisoning the direction taken by Lewis and his contemporaries. I explain why Menzel has taken this new approach, and then move into another new approach, this time given by Stephen Yablo. I discuss how these two approaches can help serve each other in helpful ways. But, at last, I present several hurdles these two views would have to overcome in order to play together nicely.

Text in German / The present dissertation considers the historical and theological foundations of radical evangelicalism and puts it in the context of theologies which influenced it and are similar to it. It will be demonstrated that the evangelicals are enriched by radical evangelicalism - an evangelical basic concept with elements of anabaptism, the social gospel, liberation theology and the ecumencial theologies. Thus it will be demonstrated that radical theology is genuinely evangelical, yet is capable of overcoming the one sidedness of western evangelical theology. Special attention is given to the contributions of radicals from North America as well as from Latin America since they are of considerable importance to radical evangelicalism. The aim of the dissertation is to present radical evangelicalism, to critically evaluate it, and to make it profitable to the European evangelical scene. The first section names the sources from which radical theology flowed. The second section reviews the historical development of radical evangelicalism. It will be demonstrated that, in the thirty years of its existence, radical evangelicalism has become a significant factor within the worldwide evangelical movement. The third section presents the fundamental characteristics of radical theology within a selection of themes. It demonstrates that the radicals have confronted the evangelical movement with a transforming theory of mission, which shows itself to be relevant for today's pressing problems. The fourth section describes the social action of radical evangelicalism and demonstrates that the energetic theology of the radicals is in fact based on a compelling spirituality. The fifth section records the results of the investigation and presents conclusions for praxis and further theological study. / Die voriiegende Dissertation erfasst die geschichtlichen und theologischen Grundlinien des radikalen Evangelikalismus und stellt ihn in den Kontext ahnlicher und ihn beeinflussender Theologien. Es wird aufgezeigt, dass der radikale Evangelikalismus eine evangelikale Grundkonzeption mit Elementen des Anabaptismus, des Social Gospel, der Befreiungstheologie und der Theologien im Umfeld des Okumenischen Rates der Kirchen bereichert Dabei wird deutlich, dass die radikale Theologie genuin evangelikal ist, die Einseitigkeiten der westlichen evangelikalen Theologie aber zu uberwinden vermag. Besondere Aufmerksamkeit ist den Beitragen radikaler Nord- und Lateinamerikaner gewidmet, da diese den radikalen Evangelikalismus wesentlich gepragt haben. Ziel ist es, den radikalen Evangelikalismus darzustellen, kritisch zu wiirdigen und fur die europaische evangelikale Szene fruchtbar zu machen. Der erste Teil nennt die Quellen, aus denen sich die radikale Theologie speist. Der zweite Teil zeichnet den geschichtlichen Werdegang des radikalen Evangelikalismus nach. Es wird nachgewiesen, dass der radikale Evangelikalismus in den dreissig Jahren seines Bestehens zu einem bestimmenden Faktor in der weltweiten evangelikalen Bewegung geworden ist. Der dritte Teil stellt die Grundzuge der radikalen Theologie mittels ausgewahlter Themen dar. Er zeigt auf, dass die Radikalen die evangelikale Bewegung mit einer transformatorischen Missionstheorie konfrontiert haben, die relevant fur die drangenden Probleme der Gegenwart ist. Der vierte Teil stellt die soziale Aktion des radikalen Evangelikalismus dar und zeigt auf, dass die energische Theologie der Radikalen im Grande genommen zur Tat driingende Spirituality ist. Der funfte Teil halt die Ergebnisse der Untersuchung fest und zieht Folgerungen fur die Praxis und das weitere theologische Arbeiten. / Christian Spirituality, Church History and Missiology / M.Th. (Missiology)

Text in German / The present dissertation considers the historical and theological foundations of radical evangelicalism and puts it in the context of theologies which influenced it and are similar to it. It will be demonstrated that the evangelicals are enriched by radical evangelicalism - an evangelical basic concept with elements of anabaptism, the social gospel, liberation theology and the ecumencial theologies. Thus it will be demonstrated that radical theology is genuinely evangelical, yet is capable of overcoming the one sidedness of western evangelical theology. Special attention is given to the contributions of radicals from North America as well as from Latin America since they are of considerable importance to radical evangelicalism. The aim of the dissertation is to present radical evangelicalism, to critically evaluate it, and to make it profitable to the European evangelical scene. The first section names the sources from which radical theology flowed. The second section reviews the historical development of radical evangelicalism. It will be demonstrated that, in the thirty years of its existence, radical evangelicalism has become a significant factor within the worldwide evangelical movement. The third section presents the fundamental characteristics of radical theology within a selection of themes. It demonstrates that the radicals have confronted the evangelical movement with a transforming theory of mission, which shows itself to be relevant for today's pressing problems. The fourth section describes the social action of radical evangelicalism and demonstrates that the energetic theology of the radicals is in fact based on a compelling spirituality. The fifth section records the results of the investigation and presents conclusions for praxis and further theological study. / Die voriiegende Dissertation erfasst die geschichtlichen und theologischen Grundlinien des radikalen Evangelikalismus und stellt ihn in den Kontext ahnlicher und ihn beeinflussender Theologien. Es wird aufgezeigt, dass der radikale Evangelikalismus eine evangelikale Grundkonzeption mit Elementen des Anabaptismus, des Social Gospel, der Befreiungstheologie und der Theologien im Umfeld des Okumenischen Rates der Kirchen bereichert Dabei wird deutlich, dass die radikale Theologie genuin evangelikal ist, die Einseitigkeiten der westlichen evangelikalen Theologie aber zu uberwinden vermag. Besondere Aufmerksamkeit ist den Beitragen radikaler Nord- und Lateinamerikaner gewidmet, da diese den radikalen Evangelikalismus wesentlich gepragt haben. Ziel ist es, den radikalen Evangelikalismus darzustellen, kritisch zu wiirdigen und fur die europaische evangelikale Szene fruchtbar zu machen. Der erste Teil nennt die Quellen, aus denen sich die radikale Theologie speist. Der zweite Teil zeichnet den geschichtlichen Werdegang des radikalen Evangelikalismus nach. Es wird nachgewiesen, dass der radikale Evangelikalismus in den dreissig Jahren seines Bestehens zu einem bestimmenden Faktor in der weltweiten evangelikalen Bewegung geworden ist. Der dritte Teil stellt die Grundzuge der radikalen Theologie mittels ausgewahlter Themen dar. Er zeigt auf, dass die Radikalen die evangelikale Bewegung mit einer transformatorischen Missionstheorie konfrontiert haben, die relevant fur die drangenden Probleme der Gegenwart ist. Der vierte Teil stellt die soziale Aktion des radikalen Evangelikalismus dar und zeigt auf, dass die energische Theologie der Radikalen im Grande genommen zur Tat driingende Spirituality ist. Der funfte Teil halt die Ergebnisse der Untersuchung fest und zieht Folgerungen fur die Praxis und das weitere theologische Arbeiten. / Christian Spirituality, Church History and Missiology / M.Th. (Missiology)