The technical possibilities of biomedicine open up the opportunity to intervene in ageing itself with the aim of mitigating, reducing or eliminating it. However, before undertaking these changes or rejecting them outright, it is necessary to ask ourselves if what would be lost by doing so really has much value. This article will analyse the desirability of ageing from an individual point of view, without circumscribing this question to the desirability or undesirability of death. First, we will present the three (...) most widely used arguments to reject biomedical interventions against ageing. We will argue that only the last of these arguments provides a consistent answer to the question of the desirability of ageing. Second, we will show that the third argument falls prey to a conceptual confusion that we will call the paradox of ageing: although ageing entails negative health effects, it leads to a life stage with valuable goods. Both valuations, one positive and the other negative, refer to two different dimensions of ageing: the chronological and the biological. We will defend that, by not adequately distinguishing these two types of ageing, it does not become apparent that all the valuable goods exclusive to ageing derive only from its chronological dimension. Third, we will argue that, if we just conceive ageing biologically, it is undesirable. We will elaborate on the two kinds of undesirable effects biological ageing has: direct and indirect. Finally, we will respond to potential objections by adducing that these are insufficient to weaken our argument. (shrink)

This paper seeks to develop a theory of health that aligns with the shift in contemporary medical practice and research toward a temporally extended epidemiological view of health. The paper describes how such a theory is at the core of life course based approaches to health, and finds theoretical grounding in recent work in the philosophy of biology promulgating a process theory of life.

During his celebrated 1922 debate with Bergson, Einstein famously proclaimed: “the time of the philosopher does not exist, there remains only a psychological time that differs from the physicist’s.” Einstein’s dictum, I maintain, has been metabolized by the natural sciences, which typically presuppose, more or less explicitly, the existence of a single, univocal, temporal substratum, ultimately determined by physics. This reductionistic assumption pervades much biological and biomedical practice. The chronological age allotted to individuals is conceived as an objective quantity, allowing (...) one to straightforwardly assign and compare the biological age of organisms. This essay argues that the standard practice of assessing the age and aging of organisms against the backdrop of a physical conception of time is problematic. This becomes especially evident in light of recent discoveries of various levels of senescence underlying the development of individual organisms—a phenomenon known as ‘age mosaicism.’ The bottom line is that the study of age and aging requires a biological conception of time, as opposed to a physical one. Einstein clearly wasn’t wrong about his operationalization of time in relativity theory. Still time may be less monolithic than he surmised. (shrink)

This paper argues that we can see our lives as a snapshot happening now or as a moving picture extending across time. These dual ways of seeing our lives inform how we conceive of the problem of age group justice. A snapshot view sees age group justice as an interpersonal problem between distinct age groups. A moving picture view sees age group justice as a first-person problem of prudential choice. This paper explores these different ways of thinking about age group (...) justice and illustrates them using a principle of respect for human dignity, understood in terms of reasonable support for floor level central human capabilities at each stage of life. I argue that different frames are suitable for different kinds of decisions, and each provides a true, but partial, picture of aging and age group justice. (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)

Both Medawar and Hamilton contributed key ideas to the modern evolutionary theory of ageing. In particular, they both suggested that, in populations with overlapping generations, the force with which selection acts on traits declines with the age at which traits are expressed. This decline would eventually cause ageing to evolve. However, the biological literature diverges on the relationship between Medawar’s analysis of the force of selection and Hamilton’s. Some authors appear to believe that Hamilton perfected Medawar’s insightful, yet ultimately erroneous (...) analysis of this force, while others see Hamilton’s analysis as a coherent development of, or the obvious complement to Medawar’s. Here, the relationship between the two analyses is revisited. Two things are argued for. First, most of Medawar’s alleged errors that Hamilton would had rectified seem not to be there. The origin of these perceived errors appears to be in a misinterpretation of Medawar’s writings. Second, the mathematics of Medawar and that of Hamilton show a significant overlap. However, different meanings are attached to the same mathematical expression. Medawar put forth an expression for the selective force on age-specific fitness. Hamilton proposed a full spectrum of selective forces each operating on age-specific fitness components, i.e. mortality and fertility. One of Hamilton’s expressions, possibly his most important, is of the same form as Medawar’s expression. But Hamilton’s selective forces on age-specific fitness components do not add up to yield Medawar’s selective force on age-specific fitness. It is concluded that Hamilton’s analysis should be considered neither as a correction to Medawar’s analysis nor as its obvious complement. (shrink)