In this paper we discuss Brandom's definition of necessity, which is part of the incompatibility sematnics he develops in his fifth John Locke Lecture. By comparing incompatibility semantics to standard Kripkean possible worlds semantics for modality, we motivate an alternative definition of necessity in Brandom's own terms. Our investigation of this alternative necessity will show that - contra to Brandom's own results - incompatibility semantics does not necessarily lead to the notion of necessity of the modal logic S5.

ZusammenfassungDie rasanten technischen Fortschritte in der Genomforschung ermöglichen heute schon die Sequenzierung des einzelnen menschlichen Genoms in wenigen Tagen und zu vertretbaren Kosten. In der Krebsforschung ermöglicht die genetische Sequenzanalyse, zunehmend die Defekte zu identifizieren, die für das Tumorwachstum bei jedem einzelnen Patienten verantwortlich sind. Auf dieser Basis können zielgerichteter Therapien entwickelt werden. Diese Forschung wirft jedoch auch neue, ethische Fragen auf. Diesen normativen Fragen widmet sich in Heidelberg das interdisziplinäre EURAT Projekt mit dem Ziel, ethisch und rechtlich informierte Lösungen (...) zu formulieren und zu etablieren.Dieser Beitrag gibt zum einen einen Überblick über die ethischen und klinischen Fragen, die für den Aufklärungs- und Einwilligungsprozess in die biobankbasierte Genomforschung relevant sind. Zum anderen wird als organisationsethische Antwort auf die Frage, wie eine Forschungsinstitution den verantwortungsvollen Umgang mit genetischen Informationen in Biobanken über die verschiedenen Berufsgruppen und beteiligten Institute hinweg sichern kann, ein Verhaltenskodex vorgestellt. Eine gut begründete, informierte Zustimmung und ein Verhaltenskodex sind beides Elemente einer „Best Practice Leitlinie“ und sollen den verantwortlichen Umgang aller beteiligten Mitarbeiter mit sensiblen genetischen Daten prägen. (shrink)

Die rasanten technischen Fortschritte in der Genomforschung ermöglichen heute schon die Sequenzierung des einzelnen menschlichen Genoms in wenigen Tagen und zu vertretbaren Kosten. In der Krebsforschung ermöglicht die genetische Sequenzanalyse, zunehmend die Defekte zu identifizieren, die für das Tumorwachstum bei jedem einzelnen Patienten verantwortlich sind. Auf dieser Basis können zielgerichteter Therapien entwickelt werden. Diese Forschung wirft jedoch auch neue, ethische Fragen auf. Diesen normativen Fragen widmet sich in Heidelberg das interdisziplinäre EURAT Projekt mit dem Ziel, ethisch und rechtlich informierte Lösungen (...) zu formulieren und zu etablieren.Dieser Beitrag gibt zum einen einen Überblick über die ethischen und klinischen Fragen, die für den Aufklärungs- und Einwilligungsprozess in die biobankbasierte Genomforschung relevant sind. Zum anderen wird als organisationsethische Antwort auf die Frage, wie eine Forschungsinstitution den verantwortungsvollen Umgang mit genetischen Informationen in Biobanken über die verschiedenen Berufsgruppen und beteiligten Institute hinweg sichern kann, ein Verhaltenskodex vorgestellt. Eine gut begründete, informierte Zustimmung und ein Verhaltenskodex sind beides Elemente einer „Best Practice Leitlinie“ und sollen den verantwortlichen Umgang aller beteiligten Mitarbeiter mit sensiblen genetischen Daten prägen. (shrink)

Unter den gegenwärtigen Bedingungen von Medienwandel und Erkenntnispluralismus lässt sich die Gestaltung von Philosophie kaum mehr als unerheblich übersehen. In einer historisch weit gespannten Studie unternimmt Hanno Depner eine kultur- und medienwissenschaftliche Kritik der blinden Bevorzugung von Diskursivität. Im Fokus steht die Konturierung des epistemischen Potentials von Diagrammen im Verhältnis zu Schrift und Bild. Dabei wird das Diagramm als Paradigma einer Philosophie vorgeschlagen, die sich als Orientierung versteht. Das erfordert jedoch die angemessene Berücksichtigung der ästhetischen Dimension des Diagramms, wofür (...) der Vorschlag eines »hybrid optimierten Diagramms« entwickelt wird. (shrink)

Unter den gegenwärtigen Bedingungen von Medienwandel und Erkenntnispluralismus lässt sich die Gestaltung von Philosophie kaum mehr als unerheblich übersehen. In einer historisch weit gespannten Studie unternimmt Hanno Depner eine kultur- und medienwissenschaftliche Kritik der blinden Bevorzugung von Diskursivität. Im Fokus steht die Konturierung des epistemischen Potentials von Diagrammen im Verhältnis zu Schrift und Bild. Dabei wird das Diagramm als Paradigma einer Philosophie vorgeschlagen, die sich als Orientierung versteht. Das erfordert jedoch die angemessene Berücksichtigung der ästhetischen Dimension des Diagramms, wofür (...) der Vorschlag eines »hybrid optimierten Diagramms« entwickelt wird. (shrink)

Hanno Su entwickelt den Rahmen einer erziehungswissenschaftlichen Bildungstheorie, der Bildung über den differenziellen Wissensbezug pädagogischer Kommunikation fasst. Dadurch wird die Frage ins Zentrum gerückt, wie eine ausdrücklich erziehungstheoretische Problematisierung von Bildung sich gegenüber der herkömmlichen bildungstheoretischen Problematisierung von Erziehung abhebt. Anlass dieses Aufrisses ist eine Verwunderung darüber, dass hinsichtlich der Verschränkung von Erziehung und Bildung auch in der Erziehungswissenschaft vorwiegend individual- bzw. subjekttheoretische Rahmungen der Bildungstheorie genutzt werden, anstatt sich etwa mit sozialtheoretischen Rahmungen der Erziehungstheorie als erziehungswissenschaftliche Bildungstheorie in (...) Form zu bringen. (shrink)

I teoremi di Gödel suscitano un interesse sempre crescente nella riflessione filosofica contemporanea. Rimane però in discussione fra gli studiosi come si sia arrivati alla loro scoperta e quale sia il loro significato per il dibattito sui fondamenti delle scienze. Nel volume si ripercorrono le vicende che portarono alla formulazione dei teoremi di incompletezza, a partire dall’incontro tra von Neumann e Gödel al Congresso di Königsberg nel 1930, e si indaga, riferendosi in particolare al lavoro di von Neumann, sull’impatto che (...) questi teoremi hanno avuto per il progetto hilbertiano di fondazione della matematica e delle scienze più in generale. Ne risulta un’immagine delle indagini di Hilbert meno rigida di quella finora corrente, in linea con le più recenti acquisizioni della storiografia, e soprattutto più rispettosa della stessa prassi assiomatica, che oscillava per Hilbert tra ambizioni fondazionaliste e istanze pragmatiche. È stato von Neumann a rendere esplicita, dopo la scoperta dei teoremi di Gödel, quella che si può definire come la “svolta pragmatica” nell’assiomatica. Il libro propone inoltre un chiarimento riguardo alla scoperta di von Neumann del secondo teorema di incompletezza. (shrink)

In this crisply written book, Hanno Sauer offers the first book-length treatment of debunking arguments in ethics, developing an empirically informed and philosophically sophisticated account of genealogical arguments and their significance for the reliability of moral cognition. He breaks new ground by introducing a series of novel distinctions into the current debate, which allows him to develop a framework for assessing the prospects of debunking or vindicating our moral intuitions. He also challenges the justification of some of our moral (...) judgments by showing that they are based on epistemically defective processes. His book is an original, cutting-edge contribution to the burgeoning field of empirically informed metaethics, and will interest philosophers, psychologists, and anyone interested in how - and whether - moral judgment works. (shrink)

In connecting educational theory to a neo-pragmatist social epistemology, we set out to understand education as knowledge practices that yield ‘the cultural world again’ by retelling culture or by making explicit what is implicit in culture. Recent trends in German educational studies towards holistic understanding of education demonstrate that such a holistic, non-representationalist framework is deliberately placed outside the traditional procedure of merely applying knowledge gained in the so-called foundational disciplines such as philosophy, sociology or psychology to the field of (...) education. By constructively relating Brandom's non-representational inferentialism to a re-reading of Mollenhauer's distinction of the presentation and representation of culture in and through education, we try to show that Brandom's philosophy can also be used to point out an inferentialism that is already at work in educational theory. Together, this strengthens a social theoretic account of education that explores how to conceptualise the role of knowledge in educational processes in terms of a holistic epistemology. (shrink)

Rationalists about the psychology of moral judgment argue that moral cognition has a rational foundation. Recent challenges to this account, based on findings in the empirical psychology of moral judgment, contend that moral thinking has no rational basis. In this book, Hanno Sauer argues that moral reasoning does play a role in moral judgment—but not, as is commonly supposed, because conscious reasoning produces moral judgments directly. Moral reasoning figures in the acquisition, formation, maintenance, and reflective correction of moral intuitions. (...) Sauer proposes that when we make moral judgments we draw on a stable repertoire of intuitions about what is morally acceptable, which we have acquired over the course of our moral education—episodes of rational reflection that have established patterns for automatic judgment foundation. Moral judgments are educated and rationally amenable moral intuitions. -/- Sauer engages extensively with the empirical evidence on the psychology of moral judgment and argues that it can be shown empirically that reasoning plays a crucial role in moral judgment. He offers detailed counterarguments to the anti-rationalist challenge (the claim that reason and reasoning play no significant part in morality and moral judgment) and the emotionist challenge (the argument for the emotional basis of moral judgment). Finally, he uses Joshua Greene's Dual Process model of moral cognition to test the empirical viability and normative persuasiveness of his account of educated intuitions. Sauer shows that moral judgments can be automatic, emotional, intuitive, and rational at the same time. (shrink)

What credence should we assign to philosophical claims that were formed without any knowledge of the current state of the art of the philosophical debate and little or no knowledge of the relevant empirical or scientific data? Very little or none. Yet when we engage with the history of philosophy, this is often exactly what we do. In this paper, I argue that studying the history of philosophy is philosophically unhelpful. The epistemic aims of philosophy, if there are any, are (...) frustrated by engaging with the history of philosophy, because we have little reason to think that the claims made by history’s great philosophers would survive closer scrutiny today. First, I review the case for philosophical historiography and show how it falls short. I then present several arguments for skepticism about the philosophical value of engaging with the history of philosophy and offer an explanation for why philosophical historiography would seem to make sense even if it didn’t. (shrink)

Moral judgements are based on automatic processes. Moral judgements are based on reason. In this paper, I argue that both of these claims are true, and show how they can be reconciled. Neither the automaticity of moral judgement nor the post hoc nature of conscious moral reasoning pose a threat to rationalist models of moral cognition. The relation moral reasoning bears to our moral judgements is not primarily mediated by episodes of conscious reasoning, but by the acquisition, formation and maintenance (...) ? in short: education ? of our moral intuitions. (shrink)

Für diesen Titel ist kein Beschreibungstext vorhanden.

Societies change over time. Chattel slavery and foot-binding have been abolished, democracy has become increasingly widespread, gay rights have become established in some countries, and the animal rights movement continues to gain momentum. Do these changes count as moral progress? Is there such a thing? If so, how should we understand it? These questions have been receiving increasing attention from philosophers, psychologists, biologists, and sociologists in recent decades. This survey provides a systematic account of recent developments in the understanding of (...) moral progress. We outline the concept of moral progress and describe the different types of moral progress identified in the literature. We review the normative criteria that have been used in judging whether various developments count as morally progressive or not. We discuss the prospects of moral progress in the face of challenges that claim that moral progress is not psychologically possible for human beings, and we explore the metaethical implications of moral progress. (shrink)

This paper reviews how and why ILF Neurofeedback has proven to be a parsimonious and efficient way to remediate the neuro-physiological effects of trauma. Reference is made to several large- and small-scale institutional proof of concept experimental studies each addressing a specific kind of trauma. It ends with a case report by the author working with an American combat veteran. It makes the argument that given its success that ILF Neurofeedback and Alpha-Theta training become accepted as part of an integrative (...) and holistic approach for treating survivors of trauma. (shrink)

The stronger the centrifugal forces of globalization become, the more people have to be on the move, the more uprooted they feel, the stronger the need for connection and encounter becomes. The desire for ›Heimat‹ is growing. But the digital transformation, which permeates all spheres of society and makes unexpected alliances possible, has little impact on housing, of all things. It favors new living desires that break away from old ideas of order and security and promote hybrid forms of behavior (...) and life. At the same time, the constraints of a capital-driven housing industry are intensifying and rarely correspond to the otherwise common demand-driven goals and purposes of the capitalist economic order. While the digital mode of production and distribution aims for the greatest possible diversification and thus corresponds to the ideal of changeability, the housing market proves to be structurally conservative and usually only finds outdated answers to new demands—with the consequence that a ›right living in the wrong life‹ appears affordable for only a select few. (shrink)

Moral judgements are based on automatic processes. Moral judgements are based on reason. In this paper, I argue that both of these claims are true, and show how they can be reconciled. Neither the automaticity of moral judgement nor the post hoc nature of conscious moral reasoning pose a threat to rationalist models of moral cognition. The relation moral reasoning bears to our moral judgements is not primarily mediated by episodes of conscious reasoning, but by the acquisition, formation and maintenance (...) – in short: education – of our moral intuitions. (shrink)

Philosophical and empirical moral psychologists claim that emotions are both necessary and sufficient for moral judgment. The aim of this paper is to assess the evidence in favor of both claims and to show how a moderate rationalist position about moral judgment can be defended nonetheless. The experimental evidence for both the necessity- and the sufficiency-thesis concerning the connection between emotional reactions and moral judgment is presented. I argue that a rationalist about moral judgment can be happy to accept the (...) necessity-thesis. My argument draws on the idea that emotions play the same role for moral judgment that perceptions play for ordinary judgments about the external world. I develop a rationalist interpretation of the sufficiency-thesis and show that it can successfully account for the available empirical evidence. The general idea is that the rationalist can accept the claim that emotional reactions are sufficient for moral judgment just in case a subject’s emotional reaction towards an action in question causes the judgment in a way that can be reflectively endorsed under conditions of full information and rationality. This idea is spelled out in some detail and it is argued that a moral agent is entitled to her endorsement if the way she arrives at her judgment reliably leads to correct moral beliefs, and that this reliability can be established if the subject’s emotional reaction picks up on the morally relevant aspects of the situation. (shrink)

This book develops a unified theory of moral progress. The author argues that there are mechanisms in place that consistently drive societies towards moral improvement and that a sophisticated, naturalistically respectable form of teleology can be defended. The book's main aim is to flesh out the process of moral progress in more detail, and to show how, when the right mechanisms and institutions of moral progress are matched together, they create pressure for the desired types of moral gains to manifest. (...) The first part of the book deals with two issues: the conceptual one about what moral progress is, and the broadly empirical one whether it is possible. It shows that cultural evolution successfully explains the origins of modern forms of morally welcome change. The second part argues that there is logical space for a moderate, scientifically credible form of teleology, and that the converse case for moral decline is weak. It addresses the types, drivers and institutions of moral progress that allow for the storage, transmission and cumulative improvement of our normative infrastructure over time. Finally, the third part demonstrates why moral progress cannot be accounted for in metaethically realist terms. Moral Teleology will be of interest to researchers and advanced students working in ethics, moral epistemology and moral psychology. (shrink)

In recent research, dual-process theories of cognition have been the primary model for explaining moral judgment and reasoning. These theories understand moral thinking in terms of two separate domains: one deliberate and analytic, the other quick and instinctive. -/- This book presents a new theory of the philosophy and cognitive science of moral judgment. Hanno Sauer develops and defends an account of "triple-process" moral psychology, arguing that moral thinking and reasoning are only insufficiently understood when described in terms of (...) a quick but intuitive and a slow but rational type of cognition. This approach severely underestimates the importance and impact of dispositions to initiate and engage in critical thinking – the cognitive resource in charge of counteracting my-side bias, closed-mindedness, dogmatism, and breakdowns of self-control. Moral cognition is based, not on emotion and reason, but on an integrated network of intuitive, algorithmic and reflective thinking. -/- Moral Thinking, Fast and Slow will be of great interest to philosophers and students of ethics, philosophy of psychology and cognitive science. (shrink)

The aim of this essay is to defend Walter Benjamin’s postulate that law is inherently violent in the context of modern democracies. The re-reading of Benjamin’s canonical essay “critique of violence” from the point of view of communication theory allows for a critical assessment of Jürgen Habermas’ philosophy of law. Building on Hannah Arendt’s distinction between power and violence, this essay identifies a contradiction between Habermas’ earlier concept of “the colonization of the lifeworld” and his later justification of positive law, (...) namely the failure to account for the ambivalent part law plays in discourse. Law always marks both the aim and, at the same time, the ending of political discourse; it is thereby violent precisely in its capacity as a substitute for communicative action. (shrink)

The most popular argument against moral realism is the argument from disagreement: if there are mind‐independent moral facts, then we would not expect to find as much moral disagreement as we in fact do; therefore, moral realism is false. In this paper, I develop the flipside of this argument. According to this argument from agreement, we would expect to find lots of moral disagreement if there were mind‐independent moral facts. But we do not, in fact, find much moral disagreement; therefore, (...) moral realism is false. I defend the argument, explain the empirical evidence that supports it, and show what makes this challenge novel and powerful. (shrink)

I Two Traditions. Scientific inquiry, seen in a very broad perspective, may be said to present two main aspects. One is the ascertaining and discovery of ...

Standard evolutionary explanations seem unable to account for inclusivist shifts that expand the circle of moral concern beyond strategically relevant cooperators. Recently, Allen Buchanan and Russell Powell have argued that this shows that that evolutionary conservatism – the view that our inherited psychology imposes significant feasibility constraints on how much inclusivist moral progress can be achieved – is unjustified. Secondly, they hold that inclusivist gains can be sustained, and exclusivist tendencies curbed, under certain favorable socio-economic conditions. I argue that Buchanan (...) and Powell concede too much to the evolutionary conservative, because their second point shows that conservatives are right about the first: inclusivist shifts are unrealistic where it matters most, namely under harsh social, political and economic conditions. I suggest two promising strategies for solving this problem. One is to focus on different forms of moral progress to secure the same moral gains. The other is to look beyond possible extensions of our psychological capacities altogether, by providing institutional support that renders them irrelevant. We should bypass, rather than further stretch, the constraints of our evolved psychology to make moral progress possible. (shrink)

Current developments in empirical moral psychology have spawned a new perspective on the traditional metaethical question of whether moral judgment is based on reason or emotion. Psychologists and cognitive neuroscientists such as Joshua Greene argue that there is empirical evidence that emotion is essential for one particularly important subclass of moral judgments: so-called ?deontological judgments.? In this paper, I scrutinize this claim and argue that neither the empirical evidence for Greene's dual process-theory of moral judgment nor the normative conclusions it (...) is supposed to yield can be maintained. More specifically, I argue that the evidence from neuroimaging relies on a problematic reverse inference, that the behavioral data are flawed, and that the findings from focal brain damage do not support the model. From a normative point of view, Greene fails to show that we ought to discount the intuitions that give rise to deontological judgments because they respond to morally irrelevant factors: firstly, I show that they do not pick up on the factors Greene deems to be morally irrelevant in the first place, and secondly, I argue that there generally is reason to trust our deontological intuitions. (shrink)

In this paper, I argue that recent evidence regarding the psychological basis of moral cognition supports a form of (moderate) moral abolitionism. I identify three main problems undermining the epistemic quality of our moral judgments – contamination, reliability, and bad incentives – and reject three possible responses: neither moral expertise, nor moral learning, nor the possibility of moral progress succeed in solving the aforementioned epistemic problems. The result is a moderate form of moral abolitionism, according to which we should make (...) fewer moral judgments much more carefully. (shrink)

Rationalism about the psychology of moral judgment holds, among other things, that the justifying moral reasons we have for our judgments are also the causally effective reasons for why we make those judgments. This can be called the ‘effectiveness’-thesis regarding moral reasoning. The theory that best exemplifies the thesis is the traditional conscious reasoning-paradigm. Current empirical moral psychology, however, poses a serious challenge to this thesis: it argues that in fact, emotional reactions are necessary and sufficient to account for moral (...) judgment, and that typically, moral reasoning is a matter of mere confabulation. In this survey, the empirical challenge to this thesis made by the ‘social intuitionist’ model of moral judgment and reasoning is discussed. The model claims that moral reasoning is essentially ineffective and, psychologically speaking, a matter of mere post hoc-rationalizations of cognitively impenetratable gut reactions. Several interpretations of this evidence are discussed and it is shown that there is room for a psychology of moral reasoning that can account for the available empirical evidence and yet does not have to give up the most central elements of a normative picture of moral reasoning. (shrink)

Achievements have recently begun to attract increased attention from value theorists. One recurring idea in this budding literature is that one important factor determining the magnitude or value of an achievement is the amount of effort the achiever invested. The aim of this paper is to present the most plausible version of this idea. This advances the current state of debate where authors are invoking substantially different notions of effort and are thus talking past each other. While the concept of (...) effort has been invoked in the philosophical analysis of a number of important concepts such as desert, attention, competence, and distributive justice, it has hardly ever been analyzed itself. This paper makes headway in this regard by discussing three ambiguities in the everyday notion of effort. It continues to develop two accounts of effort and shows how both of them are achievement-enhancing. (shrink)

Can’t we all disagree more constructively? Recent years have seen a dramatic increase in political partisanship: the 2013 shutdown of the US government as well as an ever more divided political landscape in Europe illustrate that citizens and representatives of developed nations fundamentally disagree over virtually every significant issue of public policy, from immigration to health care, from the regulation of financial markets to climate change, from drug policies to medical procedures. The emerging field of political psychology brings the tools (...) of moral psychology to bear on this issue. It suggests that the main conflict shaping politics today can be explained in terms of people’s moral foundations :1029–1046, 2009; Haidt 2012; Graham et al. PLOS One 7:1–13, ; cf. also Rai and Fiske Psychological Review 118:57–75, 2011): progressive liberals, it is argued, view society as consisting of separate individuals with differing values and life plans, whereas conservatives rely on a thicker notion of political morality that includes traditions, communities, and values of purity. In this paper, I explore the normative implications of this theory. In particular, I will argue that its proponents take it to support an asymmetry of understanding: if deep political disagreements reflect differences in people’s moral foundations, and these disagreements cannot be rationally resolved, then overcoming them makes it necessary to acknowledge the moral foundations of the other side’s political outlook. But conservatives, the theory suggests, already do acknowledge all of the liberal moral foundations, and not vice versa. To overcome partisanship and the resulting political deadlock, then, it seems to be up to liberals to move closer towards the conservative side, and not vice versa. I wish to analyze what the argument for this asymmetry is and whether it holds up. In the end, I shall argue that the available evidence does support an asymmetry, but that it is the opposite of what Moral Foundations theorists think it is. There is such an asymmetry - but its burden falls on the conservative side. (shrink)

In this paper, we argue that the so-called Knobe-Effect constitutes an error. There is now a wealth of data confirming that people are highly prone to what has also come to be known as the ‘side-effect effect’. That is, when attributing psychological states—such as intentionality, foreknowledge, and desiring—as well as other agential features—such as causal control—people typically do so to a greater extent when the action under consideration is evaluated negatively. There are a plethora of models attempting to account for (...) this effect. We hold that the central question of interest is whether the effect represents a competence or an error in judgment. We offer a systematic argument for the claim that the burden of proof regarding this question is on the competence theorist. We sketch an account, based on the notion of the reactive attitudes, that can accommodate both the idea that these sorts of judgments are fundamentally normative and that they often constitute errors. (shrink)

Keine ausführliche Beschreibung für "Die Überwindung des mathematischen Erkenntnisideals" verfügbar.

Guided by the example of gauge transformations associated with classical Yang-Mills fields, a very general class of transformations is considered. The explicit representation of these transformations involves not only the independent and the dependent field variables, but also a set of position-dependent parameters together with their first derivatives. The stipulation that an action integral associated with the field variables be invariant under such transformations gives rise to a set of three conditions involving the Lagrangian and its derivatives, together with derivatives (...) of the functions that define the transformations. These invariance identities constitute an extension of the classical theorem of Noether to general transformations of this kind. An application to the case of gauge fields demonstrates the existence of two distinct types of conservation laws for such fields. (shrink)

A certain class of geometric objects is considered against the background of a classical gauge field associated with an arbitrary structural Lie group. It is assumed that the components of these objects depend on the gauge potentials and their first derivatives, and also on certain gauge-dependent parameters whose properties are suggested by the interaction of an isotopic spin particle with a classical Yang-Mills field. It is shown that the necessary and sufficient conditions for the invariance of the given objects under (...) a finite gauge transformation are embodied in a set of three relations involving the derivatives of their components. As a special case these so-called invariance identities indicate that there cannot exist a gauge-invariant Lagrangian that depends on the gauge potentials, the interaction parameters, and the4-velocity components of a test particle. However, the requirement that the equations of motion that result from such a Lagrangian be gauge-invariant, uniquely determines the structure of these equations. (shrink)