Do you have free will?
Most people would say 'yes' to that question. How can you have free will if your body just follows the laws of science? In your brain are brain cells (neurons) which follow the law of physics and chemistry. If there is the right conditions it fire off an electrical signal. Without the right conditions it wont. Since this is based on chemistry it is automatic. One thing causes another to occur. We call this causality and it is automatic. (Now there are some who use some advanced physics concepts such as Heidegger's uncertainty principle to debate this, but properly understood any of these concepts can't deny human free will. See some of the links to the right to explore these deeper questions.) If our bodies are just causal then we can't have free will. But any rational person knows we do. So how can we have free will if my body on its own can't have free will?
We must have a soul that gives us free will. Once we realise this we can have start to develop a proper understanding of the human person. The study of the human person is called anthropology. All humans have a body and a soul. Without a body and a soul we are not fully human. Materialists believe we only have a body. Some scientists don't believe we have a soul. Science itself is not capable of exploring the reality of the soul since you can't experiment on a soul, nor detect it. So to believe you don't have a soul is not science, but can be labelled scientism which is a philosophy that believes science can answer questions it is incapable of answering such as whether God exists or whether you have a soul or not.
Really we have actually established two things, that you have a will and that it is free.
Every human has a body and soul. Without a body and a soul you are not fully human. Your soul is the basis of your free will. You body on its own would only follow causality (one thing causing another) if you didn't have a soul. Anthropology is the study of the humanity. Science can't do science on the human soul. To think that it can is called scientism, an erroneous philosophical belief that science can answer more questions than it is capable of. Materialism believes there is no spiritual side to things (or people) therefore doesn't believe we have a soul.