There are three theories of free will and determinism that you will need to be aware of:
Hard Determinism is the theory that human behavior and actions are wholly determined by external factors, and therefore humans do not have genuine free will or ethical accountability.
There are several different supporting views for this belief, which incorporates philosophical determinism, psychological determinism, theological determinism and scientific determinism.
Soft Determinism is the theory that human behavior and actions are wholly determined by causal events, but human free will does not exist when defined as the capacity to act according to one's nature (which is shaped by external factors such as heredity, society and upbringing)
Libertarianism is the theory that humans do have genuine freedom to make a morally undetermined decision, although our moral behavior may be partially determined by external factors
Like all forms of hard determinism, philosophical determinism is based on the theory of Universal Causation
Universal Causation is the belief that everything in the universe including all human actions and choices have a cause. All these events are causally determined and theorectically preditable; you just need to know the effect of the causes (a mechanistic philosophy, put forward in the Cosmological argument by Aquinas)
The Illusion of Moral Choice = the illusion of moral choice is a result of our ignorance of what causes these choices, leading us to believe they have no cause.
John Locke is the philosopher who used an analogy in which a sleeping man is locked in a darkened room. On awakening he decides he will remain in the room, unaware that the room is locked. In reality the man has no freedom to choose, he cannot get our of the room. However, his ignorance of his true condition had led him to believe that he does have the freedom
David Hume is a radical empiricit who was actually a soft determinist but contributed to philosophical determinism by commenting that we can observe patterns in the physical world that can also be found in the decisions we make. Our decisions thus, just like the physical world, are causally determined. Theoretically then, we could know the future if we were knowledgeable of all the causes in the universe and their effects
Benedict Spinoza "In the mind there is no absolute or freewill; but the mind is determined to will this or that by a cause, which has been determined by another cause, and this last by another cause, and so on until infinity"
Psychology is the study of human behavior. According to Psychological determinism, all human behavior, thoughts and feelings are the inevitable outcome of complex psychological laws describing cause and effect relationships in human behavior, Thus all decisions and actions can theoretically be predicted. There are many influencing factors on human behavior:
In the court of law the punishment of the accused is not purely determined by the extent of the crime, but diminished responsibility takes…