PARAGRAPH: Belief in free will and determinism has been a major source of contention for philosophers and psychologists for millennia, but more recent research is starting to show that belief in such things have practical implications for shaping behaviour. the notion of free will suggests that humans are free to choose our own thoughts and actions, and Libet (1985) said an act is regarded as voluntary if it arises endogenously, there are no externally imposed restrictions and that the subject feels they are performing an act on their own initiative. For the purposes of this essay, determinism then, will be considered as both opposite to an mutually exclusive of free will. Determinism is the view that all events are determined by previously existing causes, and the world is governed by cause and effect, therefore humans are not choosing their actions, and cannot have free will. These stances have been shown to affect our behaviour in that peoples prosocial behaviours change, their attitudes to judiciary issues are different, and their motivation and expectations of achieving goals might differ, which will all be discussed in this essay