The English philosopher John Locke identified the three natural rights of man as Life, Liberty and Property. The American Declaration of Independence refers to the closely related Life, Liberty and the Pursuit of Happiness. The French Declaration of the Rights of Man and of the Citizen includes freedom of religion, freedom of speech and freedom of assembly.
In laws, these are often expressed through negation: rather than a citizen having the positive "right" to live, the natural right to "life" is expressed in the terms that one citizen does not have the right to kill another. While the actions of another citizen against another can be punishable by law, there are some factors—such as illness or natural accident—that can impede on a citizen's vitality that are not (and cannot be) punishable by law.
Furthermore, these rights that are called "natural" were only considered in these terms in the seventeenth century. It is clear that rather than being "natural" and "inalienable," these rights are rather the product of liberal thinkers who regarded them as the most important for citizens to demand from their governments. It is clear that the cultural ideals of the Enlightenment heavily influenced the development of these ideas, making "natural" and "inalienable" rights the product of social ideologies. For instance, Medieval Europe would not have considered these rights as natural or inalienable, as the dominant ideology of the period would have flown directly in the fact of this assertion.