Freedom and Justice have always been challenged. Since the most remote times, and in the most varied circumstances of places and people, human beings have tried to clarify and put into practice these two controversial concepts. Freedom and Justice, in effect, are words, but also dreams, desires and practices that, not being imperfect, are less sublime and ambitious. Reflecting on them on the basis of an ethics of development and socioenvironmental sustainability is still a great challenge in our contemporaneity. This book is born from the need that we all have to reflect, understand what our role is in relation to the OTHER, understood as the other as Environment. Doing this from such disparate areas and at the same time as current as Economics, Philosophy and Ecology, is still a great opportunity to discuss complexity, transdisciplinarity and the inclusion of diverse themes, but which all converge in the Human Being and its relationship with the world. Endowing human beings with Freedom and a sense of Justice means RESPONSIBILITY. To be free and to want a better and fairer world is to endow our existence with meaning and meaning. Agency, autonomy, functioning, dignity, rights, are capacities that must be leveraged individually and collectively for authentic development to exist. Development as Freedom is a valid proposal for thinking about a socio-environmental rationality that interferes in the controversial relations between economics, ethics and the environment.