This paper explains basic ideas of Gonzalo Herranz on research ethics, in general and on human beings, obtained from the study of the fragmentary material that has been preserved (drafts and class outlines). Among other ideas, I present his thoughts on the ethical foundations of the researcher's actions: the target of the researcher, the active and passive duty to investigate, the freedom of research and the peculiarities of the relationship between the researcher and the subject of research/patient.