Denis Goulet (1931-2006) was a pioneer of human development theory and the main founder of work on “development ethics” as a self-conscious field that, by his definition, treats the ethical and value questions posed by development theory, planning, and practice. The paper looks at aspects of Goulet’s work in relation to four issues concerning the project of development ethics—[1] scope, [2] methodology, [3] roles, [4] organisational format and identity. It compares his views with subsequent trends in the field and suggests lessons for work on human development. [1] Goulet’s definition of the scope of development ethics remains serviceable and allows us to combine a view of it as social change ethics (including global change ethics) with yet a relatively specific primary audience of those who recognize themselves as working in development studies or development policy. [2] His approach in development ethics espoused intense existential immersion in each context and was often deeply illuminating, but was limited by the time and skills it requires and its relative disconnection from communicable theory. [3] Goulet wrote profoundly about ethics’ possible lines of influence, through prophetic force and more routinely through incorporation in methods, movements, and education. His own ideas did not become sufficiently embodied in methods and methodologies, but some have become so thanks to other authors. [4] Goulet saw development ethics as a new discipline or subdiscipline. However the required types of immersion, in particular contexts and/or in understanding and changing the methods and systems that structure routine practice, have to be undertaken by people coming from and remaining close to diverse disciplinary and professional backgrounds. Development ethics is and has to be, he gradually came to accept, not a distinct subdiscipline but an interdisciplinary field.