Many of us, as we get older, become curious about relatives we hardly or never knew. Perhaps, if we have children of our own, we become more aware of the biological ties that bind us to those relatives and seek self-illumination through the lighting of the shadowy places in our ancestry. This process is beautifully implied by Peter Singer’s title, Pushing Time Away, a phrase taken from a letter written by his maternal grandfather, David Ernst Oppenheim, to his maternal grandmother, Amalie Pollak, in which Oppenheim declares: ‘what binds us pushes time away.’

Singer never knew his grandfather, but was prompted to discover him on learning that Oppenheim ‘wrote about fundamental values, and what it is to be human’. For Singer, who apparently rather surprised his family by deciding to be a philosopher, this was a spur to enquiry. Moreover, ‘[t]he handful of people who knew my grandfather are getting old’. If anything, indeed, bound Singer and Oppenheim together, it had to be found now, or not at all.