Stephen Mulhall in the London Review of Books:
For David Edmonds, and for many other philosophers, Derek Parfit, who died in 2017, was one of the greatest moral thinkers of the past century, perhaps even since John Stuart Mill. Edmonds rightly believes that if Parfit’s ideas about personal identity, rationality and equality were absorbed into our moral and political thinking, they would radically alter our beliefs about punishment, the distribution of social resources, our relationship to future generations, and more. So it’s easy to see why he wants to make Parfit’s ideas more widely known outside the academy. What is less easy to understand is his belief that the best, or even an appropriate, way of achieving this goal is to write a biography of him.
There was a time when biographies of philosophers weren’t just common, but expected and even required. Following Socrates, the great schools of Hellenistic philosophy (the Stoics, the Epicureans, the Neoplatonists) all tried to encourage the pursuit of a certain kind of life. For them, philosophy wasn’t primarily something you learned, but something you practised, with a view to self-transformation. So it was indispensable in critically evaluating a philosopher to critically evaluate their way of life, for that life was the definitive expression of their philosophy, and their writings were primarily a means of achieving that essential work on the self.
More here.