I argue for the causal character of modeling in data-intensive science, contrary to widespread claims that big data is only concerned with the search for correlations. After discussing the concept of data-intensive science and introducing two examples as illustration, several algorithms are examined. It is shown how they are able to identify causal relevance on the basis of eliminative induction and a related difference-making account of causation. I then situate data-intensive modeling within a broader framework of an epistemology of scientific (...) knowledge. In particular, it is shown to lack a pronounced hierarchical, nested structure. The significance of the transition to such “horizontal” modeling is underlined by the concurrent emergence of novel inductive methodology in statistics such as non-parametric statistics. Data-intensive modeling is well equipped to deal with various aspects of causal complexity arising especially in the higher level and applied sciences. (shrink)

Recent claims, mainly from computer scientists, concerning a largely automated and model-free data-intensive science have been countered by critical reactions from a number of philosophers of science. The debate suffers from a lack of detail in two respects, regarding the actual methods used in data-intensive science and the specific ways in which these methods presuppose theoretical assumptions. I examine two widely-used algorithms, classificatory trees and non-parametric regression, and argue that these are theory-laden in an external sense, regarding the framing of (...) research questions, but not in an internal sense concerning the causal structure of the examined phenomenon. With respect to the novelty of data-intensive science, I draw an analogy to exploratory as opposed to theory-directed experimentation. (shrink)

Analogical reasoning addresses the question how evidence from various phenomena can be combined and made relevant for theory development and prediction. In the first part of my contribution, I review some influential accounts of analogical reasoning, both historical and contemporary, focusing in particular on Keynes, Carnap, Hesse, and more recently Bartha. In the second part, I sketch a general framework. To this purpose, a distinction between a predictive and a conceptual type of analogical reasoning is introduced. I then take up (...) a common intuition according to which analogical inferences hold if the differences between source and target concern only irrelevant circumstances. I attempt to make this idea more precise by addressing possible objections and in particular by specifying a notion of causal irrelevance based on difference making in homogeneous contexts. (shrink)

It is argued that in deterministic contexts evidence for causal relations states whether a boundary condition makes a difference or not to a phenomenon. In order to substantiate the analysis, I show that this difference/indifference making is the basic type of evidence required for eliminative induction in the tradition of Francis Bacon and John Stuart Mill. To this purpose, an account of eliminative induction is proposed with two distinguishing features: it includes a method to establish the causal irrelevance of boundary (...) conditions by means of indifference making, which is called strict method of agreement, and it introduces the notion of a background against which causal statements are evaluated. Causal statements thus become three-place-relations postulating the relevance or irrelevance of a circumstance C to the examined phenomenon P with respect to a background B of further conditions. To underline the importance of evidence in terms of difference/indifference making, I sketch two areas, in which eliminative induction is extensively used in natural and engineering sciences. One concerns exploratory experiments, the other engineering design methods. Given that a method is discussed that has been used for centuries, I make no claims to novelty in this paper, but hope that the combined discussion of several topics that are still somewhat underrepresented in the philosophy of science literature is of some merit. (shrink)

This book addresses controversies concerning the epistemological foundations of data science: Is it a genuine science? Or is data science merely some inferior practice that can at best contribute to the scientific enterprise, but cannot stand on its own? The author proposes a coherent conceptual framework with which these questions can be rigorously addressed. Readers will discover a defense of inductivism and consideration of the arguments against it: an epistemology of data science more or less by definition has to be (...) inductivist, given that data science starts with the data. As an alternative to enumerative approaches, the author endorses Federica Russo’s recent call for a variational rationale in inductive methodology. Chapters then address some of the key concepts of an inductivist methodology including causation, probability and analogy, before outlining an inductivist framework. The inductivist framework is shown to be adequate and useful for an analysis of the epistemological foundations of data science. The author points out that many aspects of the variational rationale are present in algorithms commonly used in data science. Introductions to algorithms and brief case studies of successful data science such as machine translation are included. Data science is located with reference to several crucial distinctions regarding different kinds of scientific practices, including between exploratory and theory-driven experimentation, and between phenomenological and theoretical science. Computer scientists, philosophers and data scientists of various disciplines will find this philosophical perspective and conceptual framework of great interest, especially as a starting point for further in-depth analysis of algorithms used in data science. (shrink)

A difference-making account of causality is proposed that is based on a counterfactual definition, but differs from traditional counterfactual approaches to causation in a number of crucial respects: it introduces a notion of causal irrelevance; it evaluates the truth-value of counterfactual statements in terms of difference-making; it renders causal statements background-dependent. On the basis of the fundamental notions 'causal relevance' and 'causal irrelevance', further causal concepts are defined including causal factors, alternative causes, and importantly inus-conditions. Problems and advantages of the (...) proposed account are discussed. Finally, it is shown how the account can shed new light on three classic problems in epistemology, the problem of induction, the logic of analogy, and the framing of eliminative induction. (shrink)

The old antagonism between the Quinean and the Duhemian view on underdetermination is reexamined. In this respect, two theses will be defended. First, it is argued that the main differences between Quine's and Duhem's versions of underdetermination derive from a different attitude towards the history of science. While Quine considered underdetermination from an ahistorical, a logical point of view, Duhem approached it as a distinguished historian of physics. On this basis, a logical and a historical version of the underdetermination thesis (...) can be distinguished. The second thesis of the article is that the main objections against underdetermination are fatal only to the logical rendering. Taken together, the two theses constitute a defence of underdetermination. (shrink)

In this article, I present a case study of underdetermination in nineteenth-century electrodynamics between a pure field theory and a formulation in terms of action at a distance. A particular focus is on the question if and how this underdetermination is eventually resolved. It turns out that after a period of overt underdetermination, during which the approaches are developed separately, the two programmes are merged. On the basis of this development, I argue that the original underdetermination survives in hidden form (...) in ontological and methodological redundancies of the subsequent particle–field electrodynamics. Implications regarding criteria for theory choice and the realism debate are briefly addressed. (shrink)

Comparing action-at-a-distance electrodynamics in the tradition of Coulomb and Ampère with electromagnetic field theory of Faraday and Maxwell provides an example for a relation between theories, that are on a par in many respects. They have a broadly overlapping domain of applicability, and both were widely successful in explanation and prediction. The relation can be understood as an inhomogeneous reduction without a clear distinction between reducing and reduced theory. It is argued in general, when a clear hierarchy between competing theories (...) cannot be determined, the plurality of standpoints should be preserved and the bridge laws carefully developed. (shrink)

Data-intensive techniques, now widely referred to as 'big data', allow for novel ways to address complexity in science. I assess their impact on the scientific method. First, big-data science is distinguished from other scientific uses of information technologies, in particular from computer simulations. Then, I sketch the complex and contextual nature of the laws established by data-intensive methods and relate them to a specific concept of causality, thereby dispelling the popular myth that big data is only concerned with correlations. The (...) modeling in data-intensive science is characterized as 'horizontal'—lacking the hierarchical, nested structure familiar from more conventional approaches. The significance of the transition from hierarchical to horizontal modeling is underlined by a concurrent paradigm shift in statistics from parametric to non-parametric methods. (shrink)

The prospects of a causal interpretation of probability are examined. Various accounts both from the history of scientific method and from recent developments in the tradition of the method of arbitrary functions, in particular by Strevens, Rosenthal, and Abrams, are briefly introduced and assessed. I then present a specific account of causal probability with the following features: First, the link between causal probability and a particular account of induction and causation is established, namely eliminative induction and the related difference-making account (...) of causation in the tradition of Bacon, Herschel, and Mill. Second, it is shown how a causal approach is useful beyond applications of the method of arbitrary functions and is able to deal with various shades of both ontic and epistemic probabilities. Furthermore, I clarify the notion of causal symmetry as a central element of an objective version of the principle of indifference and relate probabilistic independence to causal irrelevance. (shrink)

A case study is presented of a recent proposal by the major metrology institutes to redefine four of the physical base units, namely kilogram, ampere, mole, and kelvin. The episode shows a number of features that are unusual for progress in an objective science: for example, the progress is not triggered by experimental discoveries or theoretical innovations; also, the new definitions are eventually implemented by means of a voting process. In the philosophical analysis, I will first argue that the episode (...) provides considerable evidence for confirmation holism, i.e. the claim that central statements in fundamental science cannot be tested in isolation; second, that the episode satisfies many of the criteria which Kuhn requires for scientific revolutions even though one would naturally classify it as normal science. These two observations are interrelated since holism can provide within normal science a possible source of future revolutionary periods. (shrink)

Big Data and methods for analyzing large data sets such as machine learning have in recent times deeply transformed scientific practice in many fields. However, an epistemological study of these novel tools is still largely lacking. After a conceptual analysis of the notion of data and a brief introduction into the methodological dichotomy between inductivism and hypothetico-deductivism, several controversial theses regarding big data approaches are discussed. These include, whether correlation replaces causation, whether the end of theory is in sight and (...) whether big data approaches constitute entirely novel scientific methodology. In this Element, I defend an inductivist view of big data research and argue that the type of induction employed by the most successful big data algorithms is variational induction in the tradition of Mill's methods. Based on this insight, the before-mentioned epistemological issues can be systematically addressed. (shrink)

Philosophy of physics is a small but thriving research field situated at the intersection between the natural sciences and the humanities. However, what exactly distinguishes philosophy of physics from physics is rarely made explicit in much depth. We provide a detailed analysis in the form of eleven theses, delineating both the nature of the questions asked in philosophy of physics and the methodology with which they are addressed.

Brackets and tables, circles and maps, 1554-1872 -- Early botanical networks and trees, 1766-1815 -- The first evolutionary tree, 1786-1820 -- Diverse and unusual trees of the early nineteenth century, 1817-1834 -- The rule of five, 1819-1854 -- Pre-Darwinian branching diagrams, 1828-1858 -- Evolution and the trees of Charles Darwin, 1837-1868 -- The trees of Ernst Haeckel, 1866-1905 -- Post-Darwinian nonconformists, 1868-1896 -- More late-nineteenth-century trees, 1874-1897 -- Trees of the early twentieth century, 1901-1930 -- The trees of Alfred Sherwood (...) Romer, 1933-1966 -- Additional trees of the mid-twentieth century, 1931-1943 -- The trees of William King Gregory, 1938-1951 -- Hints of new approaches, 1954-1969 -- Phenograms and cladograms, 1958-1966 -- Early molecular trees, 1962-1987 -- Notable trees of the past four decades, 1970-2010 -- Primeval branches and universal trees of life, 1997-2010. (shrink)

This paper is about time preferences, the phenomenon that the very same things are usually considered the less valuable the farther in the future they are obtained. The utilities of those things are discounted at a certain rate. The paper presents a novel normative argument for exponential discount rates, whatever their empirical adequacy. It proposes to take indexical utility seriously, i.e. utilities referring to indexical propositions (that speak of ‘I’, ‘now’, etc.) as opposed to non-indexical propositions. Economic focus is only (...) on the latter, while the former are neglected. The potential ignorance of when is now generates a difference between indexical and non-indexical utility that can be exploited for a novel argument in favour of exponential discount rates. (shrink)

"A Survey of Ranking Theory": The paper gives an up-to-date survey of ranking theory. It carefully explains the basics. It elaborates on the ranking theoretic explication of reasons and their balance. It explains the dynamics of belief statable in ranking terms and indicates how the ranks can thereby be measured. It suggests how the theory of Bayesian nets can be carried over to ranking theory. It indicates what it might mean to objectify ranks. It discusses the formal and the philosophical (...) aspects of the tight relation and the complementarity of ranks and probabilities. It closes with comparative remarks on predecessors and other philosophical proposals as well as formal models developed in AI. (shrink)

Kendall Walton’s account of make-believe takes the social dimension of imagination into account. In this paper I aim to extend this suggestion and argue that works of fiction allow for encounters with concrete (yet fictitious) persons with a distinct point of view and a discernible perspective. These encounters allow us to contrast the perspective(s) that emerge from the work with one’s own. I will then discuss two moments of the social dimension: imagining fictional scenarios is a social practice, a game (...) we play together and in which we encounter others. Both of these moments shed light on the central role of fiction for the social community in which it is embedded and show how engaging with works of fiction can contribute to the inner cohesion and to the persistence of the group. (shrink)

Der Unterricht in Medizinethik soll Medizinstudierenden die Grundlagen dafür vermitteln, in ihrer zukünftigen ärztlichen Tätigkeit gute Entscheidungen treffen zu können. Im Rahmen einer Panelstudie wird derzeit die Entwicklung moralischer Positionen, medizinethischer Kenntnisse und Motivationen von Medizinstudierenden der Ludwig-Maximilians-Universität München über den Verlauf des Studiums untersucht. Für die Datenerhebung wurde ein Fragebogen entwickelt, der medizinethische Positionen und Kenntnisse sowie Motivationen erfasst. Im Wintersemester 2009/10 wurde die erste Querschnittsuntersuchung mit Studierenden im 1., 3. und 8. Semester sowie im Praktischen Jahr durchgeführt. Die (...) Mehrzahl der Befragten verfügte über einen geringen Kenntnisstand in verschiedenen Themenbereichen des Unterrichtsfachs GTE. Rechtliche Grundlagen und praktische Umsetzung von Therapiebegrenzungsmaßnahmen waren bis ins PJ-Semester vielen Studierenden nicht bekannt. Im Verlauf des Studiums veränderten sich die Motivationen weg von der Motivation, Menschen helfen zu wollen, hin zu Wissenserwerb und dem Ergreifen eines sicheren Berufs. Obwohl viele Befragte ein hohes Interesse an medizinethischen Fragestellungen und Unterricht im Bereich GTE angaben, zeigte sich kein nachhaltiger Zuwachs an medizinethischen Kenntnissen im Laufe des Studiums. In der Zusammenschau werfen die Ergebnisse die Frage auf, inwieweit verschiedene Ausbildungskonzepte Einfluss auf die individuelle ethische Entwicklung Medizinstudierender nehmen können. Eine Untersuchung dieser Fragestellung bleibt Gegenstand weitergehender Forschung. (shrink)

English Description: Plato (429/8-349-8 BCE) founded a philosophy which has greatly impacted European intellectual history. 'Platonism' was especially influential during the Roman Empire. However, a comprehensive account of the methodological, genetic, and historical aspects of its Ethics has been lacking up to this point. Stemming from an International Conference at the University of Munster, this volume fills this lacuna. Numerous experts introduced the Ethics of Platonists of the Roman Empire in chronological sequence. The themes range from questions about basic principles (...) to the intellectual classification of ethics within the philosophy (M. Bonazzi); the psychological premises (F. Drews); the action theory (M. Perkams); and the political effect of Platonic ethics (O'Meara). These and other articles represent current research in the field as well as present the sum of the ethical problems to a wider audience in a straightforward manner. German Description: Platon (429/8 - 349/8 v. Chr.) begrundete eine Philosophie, deren Nachwirkung die europaische Geistesgeschichte nachhaltig bestimmte. Der 'Platonismus' erreichte in der romischen Kaiserzeit seinen ersten Hohepunkt. Eine umfassende Darstellung seiner Ethik, in der die systematischen, genetischen und historischen Aspekte zusammengefuhrt werden, steht jedoch bisher noch aus. Dieser Band sieht hier seine Aufgabe. Er ist das Ergebnis einer internationalen Tagung an der Universitat Munster. Zahlreiche Experten stellen die Ethik des kaiserzeitlichen Platonismus in systematischer Abfolge dar. Die Themen reichen von Grundlagenfragen nach der Verortung der Ethik innerhalb der Philosophie (M. Bonazzi) und ihren psychologischen Voraussetzungen (F. Drews) uber die platonische Tugend-, Guter- und Freiheitslehre (A. Linguiti, Ch. Tornau, Ch. Pietsch) sowie die Handlungstheorie (M. Perkams) bis hin zu den politischen Wirkungen platonischer Ethik (O'Meara). Doch wenn auch diese und weitere Beitrage die aktuelle Fachforschung reprasentieren, soll zugleich durch Allgemeinverstandlichkeit auch dem wachsenden Interesse eines weiteren Publikums an ethischen Fragestellungen Rechnung getragen werden. (shrink)

And this paper is an attempt to say precisely how, thus addressing a philosophical problem which is commonly taken to be a serious one. It does so, however, in quite an idiosyncratic way. It is based on the account of inductive schemes I have given in (1988) and (1990a) and on the conception of causation I have presented in (1980), (1983), and (1990b), and it intends to fill one of many gaps which have been left by these papers. Still, I (...) have tried to make this paper self-contained. Section 1 explains the philosophical question this paper is about; in more general terms it asks what might be meant by objectifying epistemic states or features of them and to which extent epistemic states can be objectified. The next sections introduce the basis I rely on with formal precision and some explanation; section 2 deals with induction and section 3 with causation. Within these confines, section 4 attempts to give an explication of the relevant sense of objectification and section 5 investigates the extent to which various features of epistemic states are objectifiable. The two most salient results are roughly that the relation "A is a reason for B" cannot be objectified at all and that the relation "A is a cause of B" can be objectified only under substantial, though reasonable restrictions. What has all of this to do with probability? A lot. The paper trades on a pervasive duality between probabilistic and deterministic epistemology, between a probabilistic representation of epistemic states together with a theory of probabilistic causation and another representation of epistemic states which I call deterministic because it lends itself, in a perfectly parallel fashion, to a theory of deterministic causation. Here I explicitly deal only with the deterministic side, but the duality should pave the way for further conclusions concerning objective probabilities and statistical laws. This outlook is briefly expanded in the final section 6. (shrink)

Research Integrity (RI) is high on the agenda of both institutions and science policy. The European Union as well as national ministries of science have launched ambitious initiatives to combat misconduct and breaches of research integrity. Often, such initiatives entail attempts to regulate scientific behavior through guidelines that institutions and academic communities can use to more easily identify and deal with cases of misconduct. Rather than framing misconduct as a result of an information deficit, we instead conceptualize Questionable Research Practices (...) (QRPs) as attempts by researchers to reconcile epistemic and social forms of uncertainty in knowledge production. Drawing on previous literature, we define epistemic uncertainty as the inherent intellectual unpredictability of scientific inquiry, while social uncertainty arises from the human-made conditions for scientific work. Our core argument—developed on the basis of 30 focus group interviews with researchers across different fields and European countries—is that breaches of research integrity can be understood as attempts to loosen overly tight coupling between the two forms of uncertainty. Our analytical approach is not meant to relativize or excuse misconduct, but rather to offer a more fine-grained perspective on what exactly it is that researchers want to accomplish by engaging in it. Based on the analysis, we conclude by proposing some concrete ways in which institutions and academic communities could try to reconcile epistemic and social uncertainties on a more collective level, thereby reducing incentives for researchers to engage in misconduct. (shrink)

Fast 25 Jahre nach seinem Bestseller,,Unsere postmoderne Moderne" legt Wolfgang Welsch eine neuartige und tiefer gehende Infragestellung der Moderne vor. Als zentral für die Moderne sieht er das anthropische Prinzip an: In allem ist vom Menschen auszugehen, alles ist auf den Menschen zu beziehen; der Mensch ist das Maß der Welt, die Welt ist Menschenwelt - und nichts sonst, nichts darüber hinaus. Dem stellt er kritisch eine Reihe von Phänomenanalysen und die Skizze einer Anthropologie auf evolutionärer Grundlage entgegen. Indem (...) nicht die Welt vom Menschen her, sondern zuerst einmal der Mensch von der Welt her zu begreifen ist, ist den anthropischen Spiegelspielen der Moderne der Boden entzogen, und eine neue Denklandschaft zeichnet sich ab. (shrink)

The analysis of knowledge and belief has provoked intensive discussions in philosophy and linguistics. One of the issues in this area is the semantics of attitude verbs whose complement expresses a thought about the Self of the thinking person. What is the content of my belief when I think that I am tired? Some philosophers propose it is a proposition, others think it is a property. It will be shown in this essay that existing proposals in either direction are unsatisfying. (...) The property theorist expells the subject of the predicate "tired" from the analysis; their theory is at best incomplete. The propositionalist has difficulties with the analysis of the pronoun that refers back to the subject of the attitude, as is the case with "he" in "Wolfgang believes he is tired". The present new proposal ventures the idea that a conscious person is endowed with their own Logical Space that deviates from the standard model in providing for a separate entity, the Self, as the object or target of inner thoughts about oneself. Moreover, this Logical Space leaves room for linguistic error: in such a model, subjects may be unable to correctly identify the reference of a name or may fail to identify the Self with its bearer. By contrast, reference to the Self is immune to error through misidentification, it is a paradigm case of brute indexicality. In consequence, de se pronouns are rigid designators in the sense of Kripke. The book solves several puzzles of reference failure and explores numerous consequences for the semantics of attitude reports and for possible world semantics in general. (shrink)

Hauptbeschreibung Wolfgang Pleger bietet in diesem Handbuch eine kompakte, historisch-systematische Darstellung der wichtigsten anthropologischen Konzepte der europäischen Geschichte und thematisiert die problematische Situation des Menschen in der Welt. Wie etwa in der antiken und biblischen Mythologie, wo der Mensch als sterbliches Geschöpf Gottes gilt oder der materialistischen Anthropologie, die von dem Menschen als determinierte Materie ausgeht. Von der Antike bis in die Moderne, von Homer bis Sartre, wird jedes Konzept durch drei historisch bedeutsame Positionen wichtiger Denk.

Gerechtigkeit gilt als Kardinaltugend für ein gutes und richtiges Leben. Was aber bedeutet sie inhaltlich und wie lässt sie sich begründen? Der gedankliche Mittelpunkt der Darstellung ist die epochale Neubestimmung der Gerechtigkeit durch John Rawls. Seine Theorie der Gerechtigkeit hat zu vielen Diskussionen, Weiterführungen und Gegenentwürfen Anlass gegeben, die exemplarisch vorgestellt und vier Fragestellungen zugeordnet werden: Ist ein Gesellschaftsvertrag als Grundvoraussetzung der Theorie unabdingbar? Muss nicht die Gemeinschaft als Ort der Gerechtigkeitsvorstellungen stärker betont werden? Ist der Stellenwert, den Rawls der (...) Gleichheit zuschreibt, angemessen? Gewährt er der Freiheit einen adäquaten Raum? Den Abschluss bildet ein argumentationsethischer situationsbezogener Ansatz. (shrink)

Dieser Band stellt in seinen Beiträgen an ausgewählten Beispielen moderne und antike Auffassungen von dem, was aus pädagogischer Sicht über Ethik und aus ethischer Sicht über Pädagogik gesagt wird, gegenüber. Besonders die Rolle von Unterricht durch, an und in Literatur wird dabei in den Fokus genommen.

The book demonstrates for the first time that transculturality – the mixed constitution of cultures – is by no means only a characteristic of the present, but has de facto determined the composition of cultures since time immemorial. This is demonstated using examples from the arts across all cultures and continents.

In the last decade, we have observed a continuous increase of interest in eye movement research. According to a recent investigation, eye movements are discussed in over one million publications. The number of publications with eye movement in the title or abstract has been steadily increasing over the years, with over 1,200 papers published alone in 2013. The last decade has also witnessed the emergence of many new sub-disciplines in the field of neuroscience and cognition - one of them is (...) neuroaesthetics, which refers to the [neuro-]science of aesthetic perception of art.The title and contents of our book have been inspired by a very influential research article. It is one of the most cited scientific papers of all time, published in 1959 by a team of neurophysiologists and engineers, Lettvin, McCulloch and Pitts who are considered to be the founders of modern cybernetics. Their article, "What the Frog's Eye Tells the Frog's Brain," refers to the role of internal cortical models in the communication or interfacing of the information in the outside world with the practical contextual task of the viewer. It shows how eye movements are the modality of this communication. The same duality between eye movements and internal models plays a fundamental role in humans. When we look, for example, at art, it explains those neurological processes involved in neuroaesthetics. Our book undertakes this innovative approach to neuroaesthetics. It explains this duality and discusses the communication between the artist and the viewer's aesthetic perception. It is structured into five chapters.Chapter One discusses the neurology of aesthetics, the idea of art as a form of communication, and explains perception as an active matching between a "top" (the viewer's mind) and a "down" (the viewer's sensorial machinery). It goes deep into the philosophical quandary of what beauty is in terms of art. Chapter Two is about eye movements and the scanpath theory of vision perception. It discusses the role of visual attention for controlling active vision, the meaning of mental binding and the analysis of eye movements as the key to understanding aesthetic processes. Chapter Three introduces Claude Shannon's information theory using it as a matrix into which to embed the top down active vision scanpath theory. The authors explain the main concept of neuroaesthetics as a form of communication mediated by the sequence of eye fixations. Chapter Four discusses art critique: The role of the viewer's training and expectation, the dilemma of the aesthetics of art versus non-art and how all of this affects the viewing mode. Finally, Chapter Five treats the intimacy of the artistic process, showing the unique implementation of the communicative experience between the artist and the viewer - the relation between a pictorial representation defined by the artist and modes of AWE generated in the viewer during active looking. (shrink)