The best protection against propaganda of any sort is the recognition of it for what it is. Only hidden and undetected oratory is really insidious. What reaches the heart without going through the mind is likely to bounce back and put the mind out of business. Propaganda taken in that way is like a drug you do not know you are swallowing. The effect is mysterious
 you do not know afterwards why you feel or think the way you do.
Mortimer J. Adler, How to Read a Book: The Classic Guide to Intelligent Reading