The exchange of folk thoughts and formal thoughts, especially those with broad social significance, cannot be simply understood as one-way  When researchers in the history of thought find that some great thoughts from great minds have very low origins, they may sometimes feel embarrassed  If we are allowed to regard any relatively stable society or culture as a whole
We will find that it is very difficult to draw a clear line between formal thought and its corresponding folk thought
Some great thinkers are often influenced by folk thought.