The study of the human being can be addressed from different perspectives and in the framework of wider or more restricted theoretical horizons, we obtain different results from each of them. Some very important philosophers of the modern times considered that in order to have an adequate comprehension of man, we had to fold onto ourselves and deepen the analysis of the data of conscience. Other thinkers and scholars denounced the bias and inadequacy of this approach and proposed to widen the study to the closest manifestations of human life in our history, from its Greek-Roman origin to the modern age. At the same time, this widening of the focus seemed insufficient due to being ethnocentric, and the social scientists, specially the cultural anthropologists, considered that for elaborating general theories about man it was necessary to further increase the field of study by including in it the societies that are more distant in time and space, the so called "primitive societies", which had a very different way of life compared to us. But along the last century and a half, the perspective has become even broader once the sciences of life established that human beings are animal living among other living beings, and that the unit of humanity is the biological species, which integrates into the evolutionary history of a complex and unstable set of living beings currently cohabiting Earth, a middle-sized planet of our Solar System.
The aim is, thus, analyzing and discussing this theoretical horizon and the impact of the current knowledge of life within the conception of man as an exceptional being among all those that inhabit the planet. A being with a different ontological identity compared with rest. Also, it is about guessing the reasons behind the rejection reaction over the relevance this knowledge has for a more adequate conception of the human being by most of the philosophers and researchers in social sciences.