External Sourcing- Crystal Kan

From what I could gather from the external sourcing of inspiration, a lot of the artists are inspired by their environment. They can use the past or current events as a starting point and then use their personal perspective or idea to create work. I think what sets external inspiration apart from the internal is that it begins from a shared experience, either through a group of people or over a period of time. The artist could happen to come upon it by chance or through general interest in any given topic.

I guess my main question is where does external sourcing become internal, or vice versa? Is there a work of art that is considered solely inspired by the internal or external? I think that it is hard to have just one type of influence because society can influence the artists but also become a part of a personal narrative or opinion on society.