Natural rights and legal rights

Natural rights are rights that believe it is important for all humans and animals to have. These rights are often called "inalienable", meaning they can never be taken away. 
The idea first came up in ancient times but was discussed most famously by English philosopher John Locke in the 1600's. Locke said that the most important natural rights are "Life, Liberty, and Property". In the United States Declaration of Independence, the natural rights mentioned are "Life, Liberty, and the Pursuit of Happiness". The idea was also found in the Declaration of the Rights of Man. Locke, Jefferson, and others think that the purpose of government is to protect peoples' natural rights. A social contract is an implicit agreement among the members of a society to cooperate for social benefits. There have been many times in history that natural rights have been breached by both governments and individual people.