Common Sense has it that we are responsible for what we do. Human beings are rational and morally responsible. Common sense also has it that this requires having free will. But what exactly is this thing called “free will” and do we really have it? Our growing knowledge of socialization, genetics, and the brain seems to contradict this idea. Also thinking abstractly about action, cause, and chance will easily make one wonder whether free will is possible at all. The Stoics already thought about this problem. From everyday life, we know that we are sometimes free to do as we like and sometimes not free to do as we like. We know that we cannot fly like a bird even if we like to; and when we are in chains we cannot go for a walk as we please. But does it make sense to say we are free to will as we like, or not free to will as we like? What is this think, called the “will”? It seems to be something deep inside of us, the core of our personality and our self, our soul, something spiritual, untouchable, and independent from the past and the environment. It seems to be somehow absolutely free. In the end, a choice is said to be up to us. In everyday life, there are alternatives and we make choices. It seems to us that we can do A or B, and once having done A, it seems to us that we could have equally chosen to do B. But what was the cause of our action? My soul? My brain? Me? What does it mean to say “I” did it? If the world is deterministic, as classical physics teaches us so that the past and the laws of nature together determine the present and the future, will we be free? If someone can predict what we think and feel and do, will we still call ourselves “free”? Will we be in control of what we do? Or will be we be puppets attached to the past and the laws of nature, conscious of ourselves and of the world around us, but walking around with the illusion to be free and in full control although we actually are not free and not in control because everything is predetermined? These are the questions that are dealt with i