Let me never fell into the vulgar mistake of dreaming that I am persecuted whenever I am contradicted, wrote Ralph W. Emerson in the 19th century. I wonder why did he call this mistake vulgar? Vulgar comes from the Latin word vulgus, the people. However it refers to the people in a very pejorative way, attributing the people with what is common and ordinary.
So in order to understand better what Emerson meant, let us maybe liberate the word vulgar from its connotation with the people. Let us start the other way round by asking, what does Emerson understand under the word vulgar? What is happening when someone mistakes a contradiction for a persecution? This someone short-circuits difference with attack. Instead of saying he is different or he might have a point, the contradicted gets paranoid thinking if he is not my friend he must be my enemy. Vulgar in this sense means that someone is behaving vulgar when he cannot respect the other. His formular of life is: Either me, or the other.
Vulgar then means not to accept the multiplicity and diversity of the world, not to accept that people are a plural entity.