I was very sad to hear tonight of the passing of historian Howard Zinn.  Though Zinn is best known for his seminal A People's History of The United States it is his 1970 book The Politics of History that has had the most profound effect on me.  In this book he notes “Historical writings always have some effect on us.  It may reinforce our passivity; it may activate us.  In any case, the historian cannot choose to be neutral; he writes on a moving train.”  

Zinn's work is one of the things that activated me, and led me to conclude that, as an artist, I too write on a moving train.