Religion is a broad category of social practices that people use to deal with ultimate concerns, such as life after death or the fate of humankind and the universe. In monotheistic traditions, these are often addressed through belief in gods and spirits. In more humanistic or naturalistic traditions, they are often addressed through beliefs in the broader human community or the natural world. Religion is also a way of establishing and maintaining order in society. This is done through moral codes, rituals, and the entrusting of authority to religious leaders.
Many scholars have attempted to categorize religion using a variety of definitions, including monothetic and polythetic. A monothetic definition fastens on a single property that defines the class, while a polythetic definition recognizes a number of properties that are common to or even typical of religions, without making them essential.
Some scientists, such as psychologists and neuroscientists, believe that religion evolved to satisfy emotional and psychological needs of humans, including the fear of death and a desire for meaning in life. They argue that there is a physical basis for these feelings, in the form of circuitry in the brain and neurons that react to a sense of spirituality.
Others, such as sociologists and historians, have taken a more critical approach to the concept of religion. They have pointed out that the modern semantic expansion of the word went hand in hand with European colonialism, and that we should stop treating it as if it names a real thing outside of our social constructs.