Rousseau is often credited with the authorship of this myth, which was developed in his Discourse on the Origin of Inequality Among Men and Emile (Treaty on Education).
This theory posits that the noble savage state of nature, anterior to civilization, is good and natural for humans. In the state of nature, man would be happy. Civilization would correspond to the fall of man, a perversion of its nature.
In the state of nature, man, this noble savage, comes to meet its needs as they are few, it is free and stupid. His morality is reduced to the love of self (which, contrary to self-esteem) is a positive sense of self.
However, it should not be seen in this myth a history lesson (as will Voltaire), Rousseau uses it as a theoretical fiction, to know the true nature of man.
This myth will be shown in film by François Truffaut in Wild Child.