This dissertation consists of five papers which examine relationships between value, justice, time, and wasted potential.

In Chapter 1, “Wasted Potential”, I challenge the widely accepted view that how good a life is for a person depends only on what actually happens within it, such as its pleasures, achievements, and loving relationships. Instead, I argue that it also depends on the individual’s potential: what experiences, achievements, and relationships they could have had but perhaps didn’t.

In Chapter 2, “The Shape of History”, I consider whether it is better if the history of humanity features a pattern of improvement rather than deterioration, holding other things equal. I argue that it typically is, use a broadly conservative view about value to explain that, and consider the implications of my view for matters related to the future of humanity.

In Chapter 3, “Conservatism about Prudential Value”, I argue that we have a distinctive moral reason to preserve certain prudential goods, such as loving relationships and important personal projects, even when a superior replacement is available. I then show how this view illuminates several old and new puzzles about navigating childhood, adulthood, older age, and death.

In Chapter 4, “Extension and Replacement”, I develop a novel conservative account of when and why it is better to extend the length of a happy life rather than to create a new happy life, even if the total welfare is the same in both cases. I then show how this account also applies to the choice between extension and replacement with respect to non-human animals and humanity as a whole.

In Chapter 5, “Healthspan Extension, Completeness of Life, and Justice”, I argue that justice requires that we provide people with sufficient opportunities to have a ‘complete life’, that many people currently lack such opportunities, and that unconditional access to anti-ageing technology would substantially improve the status quo.