Is free will an illusion or not? This is probably one of the most famous topics in philosophy. It is a historical topic where every philosopher has their own opinions. The opinions of many philosophers are divided when it comes to the discussion of free will. For starters, free will, as defined by Psychology Today, is the “ability to consciously make decisions that are not determined by the physics and biology of our brain. It is the idea that we are able to have some choice in how we act and assumes that we are free to choose our behavior.” Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Regarding free will, one cannot simply leave out determinism and predeterminism without discussing those terms. Determinism can be defined as “the philosophical idea that every event or state of affairs, including every human decision and action, is the inevitable and necessary consequence of antecedent states of affairs” (Philosopher of Information). Predeterminism shares the idea that “all the past, as well as the future, was determined at the origin of the universe.” St. Augustine did not deny that man had free will, but he firmly believed that God predetermined everything in advance. . So, according to St. Augustine, God has foreseen how we will live. On the other hand, rationalists such as Descartes and Spinoza do not believe that man has free will at all. They assume that God is in control of the entire universe, including our lives, and believe that God has already predestined every single life in advance. To put it simply, rationalists argued that man does not have free will, so in their opinion free will is an illusion. Spinoza, in particular, argues that “we do not control everything that happens in our bodies. Nor do we “choose” our way of thinking. Man therefore does not have a free soul. According to Saint Thomas Aquinas Online, a website dedicated to him, states that Saint Aquinas believed that man's will was free. He assumed that Man had free choices to choose from, unlike what rationalists such as Spinoza and St. Augustine claimed.