"In the 18th century during the Industrial Revolution, the moral philosopher and economist Adam Smith (1723–1790), in contrast to Locke, drew a distinction between the "right to property" as an acquired right and natural rights. Smith confined natural rights to "liberty and life". Smith also drew attention to the relationship between employee and employer and identified that property and civil government were dependent upon each other, recognizing that "the state of property must always vary with the form of government". Smith further argued that civil government could not exist without property, as its main function was to safeguard property ownership."