The culture of Graffiti does provide a philosophy to live by for those who choose it. Within the street culture, writers talk about how graffiti 'saved' their lives. The phenomenon of graffiti can also provide us with important clues to the human condition, quite apart from what the words actually say. Like most philosophies it will contradict itself. It is a protest against the capitalist system of art galleries.
Nobody can own their art, it is there for all to see.
At the same time, the artists see themselves as modern day calligraphers, transforming the alphabet, creating it in a different form. They want us to see but not understand. The culture of Graffiti excludes as the writer feels excluded. The philosophy of graffiti may not provide any answers to the big questions, but it is empowering to those who live by it.