Johannes Lenhard
Biographic Data
| ID | 3640472 |
|---|---|
| NAME | Johannes Lenhard |
| GIVEN NAMES | Johannes |
| FAMILY NAME | Lenhard |
| SIGNATURE | LENHARD J |
| AFFILIATIONS | Bielefeld University |
| ORCID | 0000-0001-7485-1578 |
| VERIFIED | Yes |
| TOTAL WORKS | 26 |
| TOTAL CITATIONS | 47 |
| AUTHOR COUNT | 25 |
| EDITOR COUNT | 1 |
| FIRST PUBLICATION YEAR | 2006 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 4 |
Engineering Ethics in Comparative Perspective
Navigating the Ambiguity of Impact Investing: How Impact Venture Capitalists Access New Markets, Founders, and Capital
Despite the growing prominence of impact investing in both research and practice, the definition of social and environmental impact remains contested. Rather than resolving the elusiveness of impact, we examine how impact venture capitalists (IVCs) leverage this ambiguity in their everyday practices. Drawing on Michel de Certeau’s philosophy of everyday life, we identify three tactical ways in which IVCs navigate this ambiguity. First, IVCs use a…
The most important thing: Wittgenstein, engineering, and the foundations of mathematics
This paper revisits Wittgenstein’s heavily criticized claims about the admissibility of inconsistencies in mathematics. It argues from the perspective of mathematics as a tool and combines material from the history and practice of engineering that makes Wittgenstein’s claims about contradiction and inconsistency look much more plausible. Against this background, the paper interprets passages from Wittgenstein, including his exchange with Alan Tur…
A child of prediction. On the History, Ontology, and Computation of the Lennard-Jonesium
Modular Homes as a New Form of Accommodation to Tackle Homelessness: A Case Study From Cambridge, England
In England, provision of temporary accommodation for people experiencing homelessness has often entailed using traditional construction approaches to deliver housing. However, recent experiments are using modular homes to provide temporary accommodation, accompanied by support services for people experiencing homelessness. Given the early nature of these trials, it is unclear what impacts these modular homes have on their occupants and how these …
Traveling with Tardis. Parameterization and transferability in molecular modeling and simulation
The English language has adopted the word Tardis for something that looks simple from the outside but is much more complicated when inspected from the inside. The word comes from a BBC science fiction series, in which the Tardis is a machine for traveling in time and space, that looks like a phone booth from the outside. This paper claims that simulation models are a Tardis in a way that calls into question their transferability. The argument is …
Proof, Semiotics, and the Computer: On the Relevance and Limitation of Thought Experiment in Mathematics
This contribution defends two claims. The first is about why thought experiments are so relevant and powerful in mathematics. Heuristics and proof are not strictly and, therefore, the relevance of thought experiments is not contained to heuristics. The main argument is based on a semiotic analysis of how mathematics works with signs. Seen in this way, formal symbols do not eliminate thought experiments (replacing them by something rigorous), but …
A transformation of Bayesian statistics: Computation, prediction, and rationality
Harm Reduction- And What Keeps Us From Embracing It Fully
In this Review essay, we examine some of the latest and needed scholarship on harm reduction: Travis Lupick's Fighting for Space: How a Group of Drug Users Transformed One City's Struggle with Addiction (2018); Jarrett Zigon's A War on People: Drug User Politics and a New Ethics of Community (2019); Kimberly Sue's Getting Wrecked: Women, Incarceration, and the American Opioid Crisis (2019); and Nancy Campbell's OD: Naloxone and the Politics of Ov…
Towards fully automated investing? How venture capitalists are making the economic future old-fashioned
Finance is increasingly datafied and automated. Anthropologists (and sociologists) have worked towards a nuanced understanding of how investing remains social and driven by people despite this observable development. My research with venture capitalists - equity investors in technology startups behind companies like Google, Amazon, Facebook, and so on - shows a more extreme case. They are still investing the 'old-school' way, driven exclusively b…
Adventure Capital by Julie Kleinman
House and Home
If asked to imagine home, most of us will come to think of a particular house or building. And, for many of us, the quintessential image of home remains the place we grew up in. This close association between house and home has long marked anthropological literature. And yet, when we imagine home, it is often not the structures themselves but the feelings, practices, and relationships within familiar spaces which give home a powerful sense of bel…
Home: Ethnographic Encounters
How is home made and negotiated by the anthropologist? Secondly, how does the researcher relate to, fight against or play with notions of home which informants bring forward? Unlike theoretically – or philosophically-oriented studies that seek to define notions of home, this collection focuses instead on how people both researcher and informant themselves act and therefore define, alter, and recreate home in everyday life. Contributions are wide-…
Holism, or the Erosion of Modularity: A Methodological Challenge for Validation
Modularity is a key concept in building and evaluating complex simulation models. My main claim is that in simulation modeling modularity tends to degenerate for reasons inherent to simulation methodology. The argument will proceed by analyzing the techniques of parameterization, tuning, and kludging. They are—to a certain extent—inevitable when building complex simulation models but erode modularity. As a result, the common account of validating…
The Great Deluge: Simulation Modeling and Scientific Understanding
Elephant and ant: The social and cognitive organization of computer simulation
The text comprises two main parts. The first part reflects on the status of simulation as scientific instrument and clarifies the relationship between modeling and instrumentation. The second part aims at investigating how simulation is organized. My main claim is that a turning point for simulation occurred around 1990 that signals a new quality of simulation in terms of its social and cognitive organization. Computational chemistry will serve a…
You Care More for the Gear Than the Geezer? Care Relationships of Homeless Substance Users in London
Care for homeless people in general and homeless substance abusers in particular has been well explored as a research topic (Fisher and Collins ; Seal ; Desjarlais ; Pleace and Quilgars ; Bevan ; Briggs ). Historically, academics have been interested in care in settings as diverse as families, hospitals, asylums, poorhouses, the criminal justice system and more recently what has been called the 'community'. In this paper, I want to look at two di…
Mit allem rechnen - zur Philosophie der Computersimulation
Im vorliegenden Buch geht es um die methodologische und epistemologische Charakterisierung der Computersimulation. Zu diesem Zweck werden Computermodelle vor der Kontrastfolie mathematischer Modelle betrachtet. Eine Strategie der Mathematisierung zielt darauf ab, komplexe Phänomene in idealisierter Form zu modellieren und so die Komplexität zu reduzieren. Die Simulation markiert das Ende dieser Strategie: Die Modelle werden nun selbst komplex und…
Disciplines, models, and computers: The path to computational quantum chemistry
Austere Kindness or Mindless Austerity: The Effects of Gift-Giving to Beggars in East London
The current austerity policies in the United Kingdom are creating a precarious situation for many people on the margins of society. Employing micro-level ethnographic analysis, this article addresses how government decisions affect people living on the street. Observations of how local policies demonize gift-giving to street people led me to revisit arguments about the positive and negative effects of gifts. Four months of fieldwork amongst peopl…
Holism, entrenchment, and the future of climate model pluralism
Computer Simulation: The Cooperation between Experimenting and Modeling
The goal of the present article is to contribute to the epistemology and methodology of computer simulations. The central thesis is that the process of simulation modeling takes the form of an explorative cooperation between experimenting and modeling. This characteristic mode of modeling turns simulations into autonomous mediators in a specific way; namely, it makes it possible for the phenomena and the data to exert a direct influence on the mo…
Simulation: Pragmatic Construction of Reality
This book examines the historical roots and evolution of simulation from an epistemological, institutional and technical perspective. Rich case studies go far beyond documentation of simulation’s capacity for application in many domains, they also explore the "functional" and "structural" debate that continues to traverse simulation thought and action. One here asks if simulation deeply transforms science, or instead constitutes a limited tool th…
Surprised by a Nanowire: Simulation, Control, and Understanding
This paper starts by looking at the coincidence of surprising behavior on the nanolevel in both matter and simulation. It uses this coincidence to argue that the simulation approach opens up a pragmatic mode of understanding oriented toward design rules and based on a new instrumental access to complex models. Calculations, and their variation by means of explorative numerical experimentation and visualization, can give a feeling for a model's be…
Models and Statistical Inference: The Controversy between Fisher and Neyman–Pearson
The main thesis of the paper is that in the case of modern statistics, the differences between the various concepts of models were the key to its formative controversies. The mathematical theory of statistical inference was mainly developed by Ronald A. Fisher, Jerzy Neyman, and Egon S. Pearson. Fisher on the one side and Neyman–Pearson on the other were involved often in a polemic controversy. The common view is that Neyman and Pearson made Fish…
Computer Simulation: The Cooperation between Experimenting and Modeling
The goal of the present article is to contribute to the epistemology and methodology of computer simulations. The central thesis is that the process of simulation modeling takes the form of an explorative cooperation between experimenting and modeling. This characteristic mode of modeling turns simulations into autonomous mediators in a specific way; namely, it makes it possible for the phenomena and the data to exert a direct influence on the mo…
Surprised by a Nanowire: Simulation, Control, and Understanding
This paper starts by looking at the coincidence of surprising behavior on the nanolevel in both matter and simulation. It uses this coincidence to argue that the simulation approach opens up a pragmatic mode of understanding oriented toward design rules and based on a new instrumental access to complex models. Calculations, and their variation by means of explorative numerical experimentation and visualization, can give a feeling for a model's be…
Holism, or the Erosion of Modularity: A Methodological Challenge for Validation
Modularity is a key concept in building and evaluating complex simulation models. My main claim is that in simulation modeling modularity tends to degenerate for reasons inherent to simulation methodology. The argument will proceed by analyzing the techniques of parameterization, tuning, and kludging. They are—to a certain extent—inevitable when building complex simulation models but erode modularity. As a result, the common account of validating…
You Care More for the Gear Than the Geezer? Care Relationships of Homeless Substance Users in London
Care for homeless people in general and homeless substance abusers in particular has been well explored as a research topic (Fisher and Collins ; Seal ; Desjarlais ; Pleace and Quilgars ; Bevan ; Briggs ). Historically, academics have been interested in care in settings as diverse as families, hospitals, asylums, poorhouses, the criminal justice system and more recently what has been called the 'community'. In this paper, I want to look at two di…
Models and Statistical Inference: The Controversy between Fisher and Neyman–Pearson
The main thesis of the paper is that in the case of modern statistics, the differences between the various concepts of models were the key to its formative controversies. The mathematical theory of statistical inference was mainly developed by Ronald A. Fisher, Jerzy Neyman, and Egon S. Pearson. Fisher on the one side and Neyman–Pearson on the other were involved often in a polemic controversy. The common view is that Neyman and Pearson made Fish…
Expert knowledge, Mode-2 and scientific disciplines: Two Contrasting Views
In the recent debate in the sociology of the sciences about transdisciplinarity, Mode-2 science is heralded as inducing a new disciplinary structure of science and scientific research. We argue that this debate can be interpreted as a continuation of an older discussion about two conflicting conceptions of interdisciplinarity that we call 'early integration' and 'late integration', the latter pleading for a strong disciplinary basis of interdisci…
Austere Kindness or Mindless Austerity: The Effects of Gift-Giving to Beggars in East London
The current austerity policies in the United Kingdom are creating a precarious situation for many people on the margins of society. Employing micro-level ethnographic analysis, this article addresses how government decisions affect people living on the street. Observations of how local policies demonize gift-giving to street people led me to revisit arguments about the positive and negative effects of gifts. Four months of fieldwork amongst peopl…
Towards fully automated investing? How venture capitalists are making the economic future old-fashioned
Finance is increasingly datafied and automated. Anthropologists (and sociologists) have worked towards a nuanced understanding of how investing remains social and driven by people despite this observable development. My research with venture capitalists - equity investors in technology startups behind companies like Google, Amazon, Facebook, and so on - shows a more extreme case. They are still investing the 'old-school' way, driven exclusively b…
Disciplines, models, and computers: The path to computational quantum chemistry
Elephant and ant: The social and cognitive organization of computer simulation
The text comprises two main parts. The first part reflects on the status of simulation as scientific instrument and clarifies the relationship between modeling and instrumentation. The second part aims at investigating how simulation is organized. My main claim is that a turning point for simulation occurred around 1990 that signals a new quality of simulation in terms of its social and cognitive organization. Computational chemistry will serve a…
Simulation: Pragmatic Construction of Reality
This book examines the historical roots and evolution of simulation from an epistemological, institutional and technical perspective. Rich case studies go far beyond documentation of simulation’s capacity for application in many domains, they also explore the "functional" and "structural" debate that continues to traverse simulation thought and action. One here asks if simulation deeply transforms science, or instead constitutes a limited tool th…
Surprised by a Nanowire: Simulation, Control, and Understanding
This paper starts by looking at the coincidence of surprising behavior on the nanolevel in both matter and simulation. It uses this coincidence to argue that the simulation approach opens up a pragmatic mode of understanding oriented toward design rules and based on a new instrumental access to complex models. Calculations, and their variation by means of explorative numerical experimentation and visualization, can give a feeling for a model's be…
Models and Statistical Inference: The Controversy between Fisher and Neyman–Pearson
The main thesis of the paper is that in the case of modern statistics, the differences between the various concepts of models were the key to its formative controversies. The mathematical theory of statistical inference was mainly developed by Ronald A. Fisher, Jerzy Neyman, and Egon S. Pearson. Fisher on the one side and Neyman–Pearson on the other were involved often in a polemic controversy. The common view is that Neyman and Pearson made Fish…
Expert knowledge, Mode-2 and scientific disciplines: Two Contrasting Views
In the recent debate in the sociology of the sciences about transdisciplinarity, Mode-2 science is heralded as inducing a new disciplinary structure of science and scientific research. We argue that this debate can be interpreted as a continuation of an older discussion about two conflicting conceptions of interdisciplinarity that we call 'early integration' and 'late integration', the latter pleading for a strong disciplinary basis of interdisci…
Computer Simulation: The Cooperation between Experimenting and Modeling
The goal of the present article is to contribute to the epistemology and methodology of computer simulations. The central thesis is that the process of simulation modeling takes the form of an explorative cooperation between experimenting and modeling. This characteristic mode of modeling turns simulations into autonomous mediators in a specific way; namely, it makes it possible for the phenomena and the data to exert a direct influence on the mo…
Holism, entrenchment, and the future of climate model pluralism
Disciplines, models, and computers: The path to computational quantum chemistry
Austere Kindness or Mindless Austerity: The Effects of Gift-Giving to Beggars in East London
The current austerity policies in the United Kingdom are creating a precarious situation for many people on the margins of society. Employing micro-level ethnographic analysis, this article addresses how government decisions affect people living on the street. Observations of how local policies demonize gift-giving to street people led me to revisit arguments about the positive and negative effects of gifts. Four months of fieldwork amongst peopl…
Mit allem rechnen - zur Philosophie der Computersimulation
Im vorliegenden Buch geht es um die methodologische und epistemologische Charakterisierung der Computersimulation. Zu diesem Zweck werden Computermodelle vor der Kontrastfolie mathematischer Modelle betrachtet. Eine Strategie der Mathematisierung zielt darauf ab, komplexe Phänomene in idealisierter Form zu modellieren und so die Komplexität zu reduzieren. Die Simulation markiert das Ende dieser Strategie: Die Modelle werden nun selbst komplex und…
The Great Deluge: Simulation Modeling and Scientific Understanding
Elephant and ant: The social and cognitive organization of computer simulation
The text comprises two main parts. The first part reflects on the status of simulation as scientific instrument and clarifies the relationship between modeling and instrumentation. The second part aims at investigating how simulation is organized. My main claim is that a turning point for simulation occurred around 1990 that signals a new quality of simulation in terms of its social and cognitive organization. Computational chemistry will serve a…
You Care More for the Gear Than the Geezer? Care Relationships of Homeless Substance Users in London
Care for homeless people in general and homeless substance abusers in particular has been well explored as a research topic (Fisher and Collins ; Seal ; Desjarlais ; Pleace and Quilgars ; Bevan ; Briggs ). Historically, academics have been interested in care in settings as diverse as families, hospitals, asylums, poorhouses, the criminal justice system and more recently what has been called the 'community'. In this paper, I want to look at two di…
Holism, or the Erosion of Modularity: A Methodological Challenge for Validation
Modularity is a key concept in building and evaluating complex simulation models. My main claim is that in simulation modeling modularity tends to degenerate for reasons inherent to simulation methodology. The argument will proceed by analyzing the techniques of parameterization, tuning, and kludging. They are—to a certain extent—inevitable when building complex simulation models but erode modularity. As a result, the common account of validating…
House and Home
If asked to imagine home, most of us will come to think of a particular house or building. And, for many of us, the quintessential image of home remains the place we grew up in. This close association between house and home has long marked anthropological literature. And yet, when we imagine home, it is often not the structures themselves but the feelings, practices, and relationships within familiar spaces which give home a powerful sense of bel…
Home: Ethnographic Encounters
How is home made and negotiated by the anthropologist? Secondly, how does the researcher relate to, fight against or play with notions of home which informants bring forward? Unlike theoretically – or philosophically-oriented studies that seek to define notions of home, this collection focuses instead on how people both researcher and informant themselves act and therefore define, alter, and recreate home in everyday life. Contributions are wide-…
Adventure Capital by Julie Kleinman
Towards fully automated investing? How venture capitalists are making the economic future old-fashioned
Finance is increasingly datafied and automated. Anthropologists (and sociologists) have worked towards a nuanced understanding of how investing remains social and driven by people despite this observable development. My research with venture capitalists - equity investors in technology startups behind companies like Google, Amazon, Facebook, and so on - shows a more extreme case. They are still investing the 'old-school' way, driven exclusively b…
Proof, Semiotics, and the Computer: On the Relevance and Limitation of Thought Experiment in Mathematics
This contribution defends two claims. The first is about why thought experiments are so relevant and powerful in mathematics. Heuristics and proof are not strictly and, therefore, the relevance of thought experiments is not contained to heuristics. The main argument is based on a semiotic analysis of how mathematics works with signs. Seen in this way, formal symbols do not eliminate thought experiments (replacing them by something rigorous), but …
A transformation of Bayesian statistics: Computation, prediction, and rationality
Harm Reduction- And What Keeps Us From Embracing It Fully
In this Review essay, we examine some of the latest and needed scholarship on harm reduction: Travis Lupick's Fighting for Space: How a Group of Drug Users Transformed One City's Struggle with Addiction (2018); Jarrett Zigon's A War on People: Drug User Politics and a New Ethics of Community (2019); Kimberly Sue's Getting Wrecked: Women, Incarceration, and the American Opioid Crisis (2019); and Nancy Campbell's OD: Naloxone and the Politics of Ov…
Modular Homes as a New Form of Accommodation to Tackle Homelessness: A Case Study From Cambridge, England
In England, provision of temporary accommodation for people experiencing homelessness has often entailed using traditional construction approaches to deliver housing. However, recent experiments are using modular homes to provide temporary accommodation, accompanied by support services for people experiencing homelessness. Given the early nature of these trials, it is unclear what impacts these modular homes have on their occupants and how these …
Traveling with Tardis. Parameterization and transferability in molecular modeling and simulation
The English language has adopted the word Tardis for something that looks simple from the outside but is much more complicated when inspected from the inside. The word comes from a BBC science fiction series, in which the Tardis is a machine for traveling in time and space, that looks like a phone booth from the outside. This paper claims that simulation models are a Tardis in a way that calls into question their transferability. The argument is …
A child of prediction. On the History, Ontology, and Computation of the Lennard-Jonesium
The most important thing: Wittgenstein, engineering, and the foundations of mathematics
This paper revisits Wittgenstein’s heavily criticized claims about the admissibility of inconsistencies in mathematics. It argues from the perspective of mathematics as a tool and combines material from the history and practice of engineering that makes Wittgenstein’s claims about contradiction and inconsistency look much more plausible. Against this background, the paper interprets passages from Wittgenstein, including his exchange with Alan Tur…
Engineering Ethics in Comparative Perspective
Epistemology (13 works) · Computer Science (11 works) · Philosophy (9 works) · Mathematics (6 works) · Philosophy and History of Science (6 works) · Sociology (6 works) · Psychology (5 works) · Art (4 works) · Artificial Intelligence (4 works) · Political science (4 works)