In its simplest form, the word “world” describes the totality of existent entities, including all humans, animals and other living organisms, to which it belongs, is and will become and by extension, everything that has or will become part of this world. The nature of this world is described differently in various disciplines. Some conceptions regard the world as having only one world, while others speak of a “plurality of worlds” simultaneously existing with each other. Still others maintain that the world is a world but exists in multiple timescales simultaneously. Still yet, some philosophers regard the world as infinite and unnameable, as is the case with some religious pantheists. Still others hold that the world consists of many different worlds, each having a temporal dimension.

A number of philosophers during the medieval period regarded the world and all the inhabitants thereof as divine beings who were responsible for the workings of the world and for its maintenance. They held that, just as man is responsible for his actions and those of his fellow creatures, so are the spirits of all the inhabitants of the world. Theologians and mystics created pictures of this celestial sphere to help people understand their place in the solar system, or the heavens, and how they are meant to interact with the rest of the living. According to some philosophers, every inhabitant of this world is an element that is part of this cosmic system.

In the medieval world, the earth, including all the inhabitants and all the things upon it, was considered sacred. This includes the earth, all the plants upon it, and all the animals, including people. Theologians and mystics used images like the tree of life and the circle of life to explain how the different things in the world were produced, how death occurred, and why there are different kinds of living beings. They explained that all the inhabitants of this world, even the animals, are part of this world and are made to participate in the activities that will shape the world into its physical form. They theorized that the earth functions to attract all the forces of the universe into itself, and that all the forces exist because they are attracted by the earth.

Some philosophers also explained how the earth was created and gave a scientific explanation as to how the world was created. According to these philosophers, the earth is a place where matter is created and which exists forever. They did not allow for any evolution of the matter or any change in the shape of matter; everything is permanent in their theory. However, these same philosophers also allowed for the possibility of intelligent life on the earth. They posited that a great quantity of living matter may be at the very foundation of the world and that the distance between the earth and the sun is so great that it creates an atmosphere within which life can occur.

The other philosophers further maintained that the earth is a place of infinite temperature, and that it is possible for life to occur only in areas that are either very cold or very hot. Therefore, the earth is not round. Aristotle, the most influential Greek philosopher, was the first one to postulate the geocentric model in his Physics. He explained how the sun, as a huge source of light, moves around the world and revolves around the earth. He further stated that the earth is spinning due to the centrifugal force of the moon and that this motion causes the rotation of the earth. Thus, Aristotle explained the movement of the heavenly bodies through a simple, but powerful, model based on planetary movements.

The other dominant school of thought in the academic world is the deflationist school which postulates that money is a commodity and that individuals have no real value apart from that which they can create for themselves through the use of money. According to this school of thought, money is a distinct class, which has no real existence outside of human interaction in markets. It is true that contemporary society has created a vast network of global interrelations, and money has indeed become part of those relations. Nevertheless, it is debatable whether money really represents a distinct category of value that is independent of human interaction. Furthermore, many people who subscribe to this school of thought maintain that deflation creates a situation where there is no demand for goods and services, and thus, there are no inhabitants to share the wealth created by the innovations of others.