The question of what it means to be a human being is a concern at least as far back as pre-Socratic philosophy, when the sophist Protagoras ventured a definition: “man is the measure of all things.” For Protagoras, being human meant being the reference point from which all else is known, as human being is the only sentient space from which we can come to know anything, including what it means to be a human. Since then, the question of what it means to be a human has been a central question not only for philosophers, but for anyone who struggled to define humanity in any terms.

Anthropological Definitions

In the scientific sense, to be human means to be a complex biological organism belonging to the species of Homo sapiens, a member of the great ape family. It means to be capable of logical reasoning, abstract thought, learning and using languages and possessing self-awareness. Furthermore, being human means you are capable of culture, complex problem solving, creating advanced technologies and developing complex social institutions. However, while all of this is factually correct, some feel that it provides only a limited description, and does not really encompass the core of what it means to be a human.

Philosophical Man

Some have defined a human as a creature who is capable of investigations regarding himself, his environment and his own meaning. This can roughly be referred to as philosophical man. Philosophical man is defined by the questions he asks about himself and his reality. For some philosophers, hailing as far back as Plato, man is defined by his particular essence, the fact that he has a soul. For others, man is defined by the radical absence of any such essence, and is instead a purely material being with purely material concerns.

Religious Man

For some people, what it means to be human is intertwined with other questions about the nature of transcendent reality as described by a particular religious doctrine. For such people, being human can mean being a manifestation of a higher power. In the Judeo-Christian tradition, for example, being human means being an imperfect creature made in the image of God, and what it means to be human is to be a servant of God. For others, such as Buddhists, it means suffering; one is human only until one attains enlightenment, at which time one returns to a oneness with transcendent reality. Of course, other definitions abound, but in general they have in common a definition of human framed by an understanding of the larger realities that stand over and above him.

Social and Political Man

For some, being a human means that one is social and political creature. In other words, humans are defined by their social interactions, and in extreme versions of this view, being human means being a manifestation of one’s larger social and cultural environment. Furthermore, human beings are inherently political creatures because they attempt to further their own interests even in relation to their social group.

Existential Man

Existentialism, a philosophical trend which took prominence in the mid 20th century, provides a definition of man which is vastly different than others. Jean-Paul Sartre, perhaps the most well-known existentialist philosopher, is famous for the dictum “existence proceeds essence,” which, when applied for man, means that he has no pre-determined defining nature but rather is responsible for making his own nature by choosing from all his possible selves. In other words, man is his own essential "nothingness" and must create his own particular "being" by taking on the responsibility of providing his own definition. Man is his own radical freedom, in that nothing constrains him save himself, and to be human means simply to be this self-defining creature, to be whatever one decides one wants to become.