Nothing of Leonardo DAVinci's sketchbooks were published until the 20th century. These are some of the most important documents of the Renaissance, and they did not become known until the 20th century. There are still people who do not know how important this work was. His anatomical studies were a watershed moment, because they introduced visual diagrams as the standard for communicating knowledge of the body and self. This was no more and no less than the conviction that the true knowledge of the shape of any body could only be arrived at by seeing it from different aspects. The truth of the body, the truth of the human being can only be discovered by looking at the body from multiple aspects, like; level, motion, perspective, transformation and growth. He opened up the body, it had always been closed, now its open. Now, what goes on inside the body is going to give us the essence of what it means to be human. It is the internal struggle, the self with the self, within .you. When you look at his sketchbooks, you see just one place where the whole world opens up.