I am trying to make art that relates to the deepest and most mythic concerns of human kind and I believe that, at this moment of history, feminism is humanism.

The quote is saying that art should relate to the most important things that concern people. The speaker also believes that feminism is currently one of the most important issues facing people in the world today. The idea is that feminism is something that affects everybody—men and women alike—which is why the speaker believes that it is a form of humanism.