What are the motifs in Siddhartha by Hermann Hesse?

Unity is always a recurring idea in this story. When Siddhartha despairs of ever finding peace, he contemplates suicide at the river. When the word "Om" comes to mind, he realizes the folly of his attempt to end his sufferings by extinguishing his physical being. Life is indestructible. Creation is an indivisible whole. He sees his great mistake in trying always to do something instead of just to be.