I was interested to read how Karl Barth is considered the father of the current turn in Christian ethics to "ecclesial ethics," meaning the work of Yoder, Hauerwas, O'Donovan, and MIlbank. I've always thought of Barth as the Great Dogmatician, and yes there is ethical thought throughout the Church Dogmatics, but I had not thought of him as an important ethicist in his own right.
According to Introducing Christian Ethics, by Samuel Wells & Ben Quash, he was the primary catalyst for this renewed interest in Christian ethics in moving beyond a rationalistic, Western, philosophical, and universal conception of ethics, and a return to a more ecclesial, church-centered approach--which makes sense, as it is the Church Dogmatics, after all. Yet I had not really thought of Barth as an ethicist in his own right, but primarily as a systematic theologian. This insight shows not only the interconnectedness of theology and ethics (and especially a theological ethics, naturally), but the huge influence of Barth on current theological thought.
Quash and Wells helpfully demarcate three approaches for Christian ethics: universal (the most common approach in ethical thought, rooted in philosophical thought, Kant, and the Enlightenment), subversive (the more recent concerns of Marxism, liberation theology, and feminism to restore context and culture to ethical thought), and then ecclesial. Ecclesial is a return to an emphasis on the church as the church; like subversive ethics, it is concerned with context and history, in contrast to the rationalistic and prescinded approach of universal ethics (where the concern is solely for any rational moral agent).
Ecclesial ethics is an attempt to remove Christian ethical thought from the university and the philosophers, and restore it to Christians and theologians actively pursuing lives of faith and action. It has certainly enlivened the study of Christian ethics.