Having analyzed these traits, we can now advance a definition of propaganda — not an exhaustive definition, unique and exclusive of all others, but at least a partial one: Propaganda is a set of methods employed by an organized group that wants to bring about the active or passive participation in its actions of a mass of individuals, psychologically unified through psychological manipulations and incorporated in an organization.

Vintage, p. 61 - Propaganda: The Formation of Men's Attitudes (1965)