Where rights come from

Natural rights. In the 17th and 18th centuries, political theorists argued that rights come from nature or God, through natural law. We are born with them; no ruler or society grants them, so they are inalienable: no one can take them away.

• They named three natural rights: life, liberty and property, from which other rights were derived.
• This powerful idea was widely used to oppose arbitrary power by states and governments and to safeguard individual freedom.

Human rights. Today the term human rights is used more, because the idea of a natural law laid down by nature or God seems unacceptable to many. Rights are now seen as guarantees that people themselves seek or arrive at to lead a minimally good life.

• The assumption: all persons are entitled to certain things simply because they are human. Each person is unique and equally valuable; no one is born to serve others; each must have equal opportunity to be free and realise their potential.
• This idea of a free and equal self is used to challenge inequalities based on race, caste, religion and gender.

Kant on human dignity. The 18th-century German philosopher Immanuel Kant wrote that everything has either a price or a dignity. What has a price can be replaced by an equivalent; what is above all price has dignity. Human beings possess dignity and are valuable in themselves.

• So every person, even if uneducated, poor, powerless, or dishonest, deserves some minimum dignity. To treat people with dignity is to treat them morally: treat others as we would like to be treated, and never treat a person merely as a means to our ends, as we would use a pen or a car. This moral conception of rights inspired struggles against social hierarchies.

The Universal Declaration of Human Rights, adopted by the UN General Assembly on 10 December 1948, recognises claims the world community sees as essential for dignity and self-respect. Oppressed people everywhere have used it to challenge segregation and unequal laws; slavery has been abolished, though other struggles have had limited success.

• The list keeps expanding as societies face new threats: concern for the environment has produced claims to clean air and water and sustainable development; awareness of what women, children and the sick suffer in war and disasters has produced claims to a right to livelihood and rights of children.

Example (new): when a city's river becomes too polluted to use, residents may claim a right to clean water, a claim that would hardly have been made a century ago: rights grow as new dangers appear.