In this book, the research is focused on that ethical thought which harmonises two elements of human action: the moment of rational and free reflection, on the one hand; and on the other, the acceptance of a natural element which is -- in a broad sense -- previously given and which serves as a basis for this reflection. Therefore, philosophers from the phenomenological tradition have been chosen, or who are sympathetic to phenomenology and recognise that ethics begins from a real, objective base. The majority of the philosophers studied here does not deal with ethical action in any direct fashion, and some do not even work on ethics qua distinct discipline. But in all of these authors an intense reflection can be found which, in various ways, leads to ethics and to the consideration of human action. Thus, many of the articles included in this collection provide a detailed presentation of the way in which the philosophers studied deal with ethical topics, prior to delving into ethics itself. This is, as is well known, a very common characteristic of 20th century philosophy.