To discuss free will and determinism, we must first define what these are. Free will is considered to be the conscious decisions we make thus making us behave in a certain way. Furthermore, behaviour can also be determined to be voluntary if it is not automatic and not done under necessity.
Free will results in an individual having responsibility for their actions, often morally. Those who suffer from mental disabilities have a reduced responsibility for their actions due to them not being considered “free to choose” the behaviour they undertake. This is considered to be an ethical, penal and societal justification for Free Will, as it allows for rewards and punishment accordingly. Oftentimes, individuals often take steps to prove their self-determination by being resistant to circumstances that may change their behaviour, such as being told to do something.
Determinism on the other hand is generally considered to be more scientific (and the way that Psychology should be treated if it were to be a science according to William James), explaining that behaviour is as a result of various external and internal factors that we do not have as much control over (we are passive responders), for example reinforcement as an outside force or genetics as an internal one. This position also states that behaviour can be predicted and that the behaviour undertaken is inevitable with no probability for other behaviours to take place. Therefore, this position is often popular because it removes the burden of moral responsibility for behaviours.
It is also important to distinguish between “choice” and “outcome”. The 18th century philosopher David Hume explained this by presenting the hypothetical situation of an individual in a room. The person is given the choice to stay in the room or leave through a door. In one instance, the individual chooses to leave through the door but finds