Edward L. Bernays 
Crystallizing Public Opinion [EPUB ebook] 

In writing this book I have tried to set down the board principles that govern the profession of public relations. It is certain that the power of public opinion is constantly increasing and will keep on increasing. It is equally certain that it is more and more being influenced, changed, stirred by impulses from below. The danger which this development contains for a progressive ennobling of human society and a progressive heightening of human culture is apparent. The duty of the higher strata of society-the cultivated, the learned, the expert, the intellectual-is therefore clear.
They must inject moral and spiritual motives into public opinion. Public opinion must become public conscience.