The Languages of Pao is based on the Sapir-Whorf Hypothesis, which states:
"Human beings do not live in the objective world alone, ... but are very much at the mercy of the particular language which has become the medium of expression for their society. ... [The] "real world" is to a large extent unconsciously built up on the language habits of the group."Edward Sapir, 'The Status Of Linguistics As A Science', 1929
In The Languages of Pao Jack Vance assumes the Sapir-Whorf Hypothesis is true; he assumes that the language spoken by a people determines how they think and act. A people's culture is a product of their language. A corollary to the Sapir-Whorf Hypothesis, then, is that by changing the language of a people one can change their culture.
" Le fait est que la "réalité" est, dans une grande mesure, inconsciemment construite à partir des habitudes linguistiques du groupe. Deux langues ne sont jamais suffisamment semblables pour être considérées comme représentant la même réalité sociale. Les mondes où vivent des sociétés différentes sont des mondes distincts, pas simplement le même monde avec d'autres étiquettes."
http://fr.wikipedia.org/wiki/Hypoth%C3%A8se_Sapir-Whorf