This special issue of the journal is a birthday issue. A fortieth birthday is usually the time for more than pure celebration: a rueful glance in the mirror at the beginning to check on grey hairs, taking stock about whether achievements come anywhere near those carefully laid plans, cautious conversations with people who've been around that long too (with a wary look at the younger ones who might have been expecting a lot more); and then a long, deep breath about what comes next.

This anniversary is no different: 1975 was indeed a special year. Many will want to know what happened then and since, and why: Alastair Campbell, as the founding editor (and writer of one of the first modern books published on clinical ethics in the UK) describes it clearly, and Gordon Stirrat's focus on teaching and Roger Higgs's on case discussion add further dimensions. But equally important questions for this birthday issue need to be posed about what medical ethics in general, and the Journal of Medical Ethics in particular, have achieved, and what they haven't; and where they should be going from here.

It was the present editor-in-chief Julian Savulescu who suggested that these questions might be addressed by making the theme of JME40 the open-ended question ‘What is it to do good medical ethics?’ We snapped up this idea. But who should we invite to answer the question? We started by asking the JME's editors past and present, and then we added our own choices. There were far too many, even for the bumper size of this special issue, and we remain desperately aware that many we should have liked to have asked have not been included. But as Kirkegaard said, to start sewing you have to knot the end of the thread, …