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)

Currently, in the United States, there is no legal obligation for medical professionals or civil courts to uphold patients’ Advance Directives (ADs) regarding end-of-life care. The applicability and standing of ADs prepared by Alzheimer’s patients is a persistent issue in bioethics. Those who argue against giving ADs full status take two main approaches: (1) appealing to beneficence on behalf of the Alzheimer’s patient and (2) claiming that there is no longer any personal equivalence between the AD’s creator and the subject (...) of the AD. In this paper, I present profound arguments against both approaches. Firstly, I argue that the principle of beneficence cannot apply in the case of Alzheimer’s patients, and, secondly, that the moral and legal authority of the AD need not depend on strict equivalence of personal identity. I conclude by arguing that valid ADs protect the dignity and autonomy of Alzheimer’s patients and that, therefore, there are moral obligations to uphold ADs which should be reflected in public policy and legislation. (shrink)

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)

Drawing on Ezekiel Emanuel’s controversial piece ‘Why I hope to die at 75,’ I distinguish two types of concern in ethical debates about extending the human lifespan. The first focusses on the value of living longer from prudential and social perspectives. The second type of concern, which has received less attention, focusses on the value of aiming for longer life. This distinction, which is overlooked in the ethical literature on life extension, is significant because there are features of human psychology (...) and the structure of a life that should give pause when considering how long one should aim to live, but which do not neatly coincide with considerations about how valuable additional life is likely to be. I argue that, while Emanuel’s case for hoping to die at 75 is unconvincing, he nonetheless provides weak pro tanto considerations in favour of taking a moderate life span as a prudential aim around which to base at least some significant life plans. (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)