Emmanuel Lévinas, the philosopher of ethics par excellence in the twentieth century, and by own merit one of the most important ethical philosophers in the history of western philosophy, is also the philosopher of the Other. Thereby, it can be said that no thought has deepened like his in the ups and downs of the ethical relationship between subject and otherness. The general objective of this work is to expose in a simple and understandable way some ideas that tend to be quite dark in the philosophical work of the author, since his profuse religious production will not be analyzed here. It is expected to show that his ideas about the being and the Other are relevant to better understand interpersonal relationships in times of 4.0 (re)evolution. As specific objectives, this work aims to expose in chronological order the main works of the thinker, with special emphasis on his ethical implications: Of the evasion (1935), The time and the Other (1947), From the existence to the existent (1947), Totality and infinity: An essay on exteriority (1961) and, last, Otherwise than being, or beyond essence (1974). In the judgment of Lévinas, history of western philosophy starting with Greece, has shown an unusual concern for the Being, this is, it has basically been an ontology and, accordingly, it has relegated ethics to a second or third plane. On the other hand and in a clear going against the tide movement, our author supports that ethics should be considered the first philosophy and more, even previous to the proper philosophize. This novel approach implies, as it is supposed, that the essential question of the philosophy slows down its origin around the Being in order to inquire about the Other: it is a philosophy in first person. Such a radical change of perspective generates an underlying change in how we conceive interpersonal relationships, the complex framework of meanings around the relationship Me and You, which also philosopher Martin Buber had already spoken of. As Lévinas postulates that ethics is the first philosophy, this involves that the Other claims all our attention, intellectual and emotional, to the point of considering that the relationship with the Other is one of the measures of our identity. Thus, “natural” attitude –husserlian word not used by Lévinas- would be to be in permanent disposition regarding to the meeting with the Other, to be in permanent opening state to let ourselves be questioned by him. Ontology, as the author says, being worried about the Being, has been likewise concerned about the Existence, when the matter is to concern about the particular Existent that every otherness supposes for us. In conclusion it can be affirmed that levinasian ethics of the meeting with the Other, particular Face, irreducible to the assumption, can contribute with an innovative looking to (re)evolving the interpersonal relationships in a 4.0 context.