The final work of a distinguished physicist, this remarkable volume examines the emotive significance of time, the time order of mechanics, the time direction of thermodynamics and microstatistics, the time direction of macrostatistics, and the time of quantum physics. Coherent discussions include accounts of analytic methods of scientific philosophy in the investigation of probability, quantum mechanics, the theory of relativity, and causality. "[Reichenbach’s] best by a good deal."—Physics Today. 1971 ed.

Prevention of age-related disorders is increasingly in focus of health policies, and it is hoped that early intervention on processes of deterioration can promote healthier and longer lives. New opportunities to slow down the aging process are emerging with new fields such as personalized nutrition. Data-intensive research has the potential to improve the precision of existing risk factors, e.g., to replace coarse-grained markers such as blood cholesterol with more detailed multivariate biomarkers. In this paper, we follow an attempt to develop (...) a new aging biomarker. The vision among the project consortium, comprising both research and industrial partners, is that the new biomarker will be predictive of a range of age-related conditions, which may be preventable through personalized nutrition. We combine philosophical analysis and ethnographic fieldwork to explore the possibilities and challenges of managing aging through bodily signs that are not straightforwardly linked to symptomatic disease. We document how the improvement of measurement brings about new conceptual challenges of demarcating healthy and unhealthy states. Moreover, we highlight that the reframing of aging as risk has social and ethical implications, as it is generative of normative notions of what constitutes successful aging and good citizenship. (shrink)

While aging research and policy aim to promote ‘health’ at all ages, there remains no convincing explanation of what this ‘health’ is. In this paper, I investigate whether we can find, implicit within the sciences of aging, a way to know what health is and how to measure it, i.e. a theory of health. To answer this, I start from scientific descriptions of aging and its modulators and then try to develop some generalizations about ‘health’ implicit within this research. After (...) discussing some of the core aspects of aging and the ways in which certain models describe spatial and temporal features specific to both aging and healthy phenotypes, I then extract, explicate, and evaluate one potential construct of health in these models. This suggests a theory of health based on the landscape of optimized phenotypic trajectories. I conclude by considering why it matters for more candidate theories to be proposed and evaluated by philosophers and scientists alike. (shrink)

Most contemporary models of disease development consider the interaction between genotype and environment as static. The authors argue that because time is a key factor in genotype–environment interaction, this approach oversimplifies the pathology analysis and may lead to wrong conclusions. In reviewing the field, the authors suggest that the history of genotype–environment interactions plays an important role in the development of diseases and that this history may be analyzed using the phenotype as a proxy. Furthermore, a theoretical and experimental framework (...) is proposed based on the assumption that phenotypes do not change from one to another randomly but are interconnected and follow certain phenotype trajectories. It then follows that analysis of such phenotype trajectories might be useful to predict the future phenotypes including the onset of disease. In addition, an analysis of phenotype trajectories can be subsequently used to choose better control subjects in comparative studies reducing noise and bias in studies investigating disease mechanisms. (shrink)

On April 6, 1922, in Paris, Albert Einstein and Henri Bergson publicly debated the nature of time. Einstein considered Bergson’s theory of time to be a soft, psychological notion, irreconcilable with the quantitative realities of physics. Bergson, who gained fame as a philosopher by arguing that time should not be understood exclusively through the lens of science, criticized Einstein’s theory of time for being a metaphysics grafted on to science, one that ignored the intuitive aspects of time. The Physicist and (...) the Philosopher tells the remarkable story of how this explosive debate transformed our understanding of time and drove a rift between science and the humanities that persists today. -/- Jimena Canales introduces readers to the revolutionary ideas of Einstein and Bergson, describes how they dramatically collided in Paris, and traces how this clash of worldviews reverberated across the twentieth century. She shows how it provoked responses from figures such as Bertrand Russell and Martin Heidegger, and carried repercussions for American pragmatism, logical positivism, phenomenology, and quantum mechanics. Canales explains how the new technologies of the period—such as wristwatches, radio, and film—helped to shape people’s conceptions of time and further polarized the public debate. She also discusses how Bergson and Einstein, toward the end of their lives, each reflected on his rival’s legacy—Bergson during the Nazi occupation of Paris and Einstein in the context of the first hydrogen bomb explosion. -/- The Physicist and the Philosopher reveals how scientific truth was placed on trial in a divided century marked by a new sense of time. (shrink)

This paper addresses a philosophical problem concerning the ontological status of age classification. For various purposes, people are commonly classified into categories such as “young adulthood”, “middle adulthood”, and “older adulthood”, which are defined chronologically. These age categories prima facie seem to qualify as natural kinds under a homeostatic property cluster account of natural kindhood, insofar as they capture certain biological, psychological, and social properties of people that tend to cluster together due to causal processes. However, this is challenged by (...) the observation that age categories are historically unstable. The properties that age categories are supposed to capture are affected by healthcare and cultural developments, such that people are staying biologically, psychologically, and socially young for longer. Furthermore, the act of classifying people into age categories can bring about changes in their behaviors, which in turn alter the biological, psychological, and social properties that the categories are supposed to capture. Accordingly, I propose that age categories are best understood as interactive kinds that are influenced in dynamic ways by looping effects. I consider some implications of these looping effects for our classificatory practices concerning age, including how different disciplines may need to review the ways they define and use age categories in their inductive inferences. (shrink)

In the paper, after clarifying terms such as ‘identity’, ‘self’ and ‘personhood’, I propose an empirical account of identity based on the notion of “whole phenotype”. This move allows one to claim the persistence of the individuals before and after their being affected by dementia. Furthermore, I show how this account permits us to address significant questions related to demented individuals’ loss of the capacity of moral decisions.