Two theories exists, Libertarianism and Hard Determinism.
Libertarianism is the belief that all your actions are independent of everything but your free will. For example, I wanted to eat chicken for breakfast simply because I feel like it, right?
Not quite.
That premise is rebutted by saying that even ‘feelings’ is pre-determined and outside our control. As a counter-rebuttal, Libertarianism concedes that the physical world IS outside our control but our mental faculty (anything that is propelled by mind) is IN our control. This mental faculty enables multiple possibilities of events (Example: The physical world provides my fridge with chicken, beef and duck, but MY mental faculty decides which one to eat), which means that we are in control of our actions. They also say that we can’t just disregard our ‘feelings’ because it IS the manifestation of our free will.
On the contrary, Hard Determinism believes that everything in this universe is pre-determined, that everything that happened in this universe is the inevitable cause of a previous event. That there is no such thing as ‘multiple possibilities’ because every bit of your action is 100% influenced by things outside our control.
Hard Determinists’ analysis to the Chicken-Beef-Duck scenario is that even our mental faculty IS part of the physical world.
Mental faculty = Brain = Biological world = PHYSICAL WORLD.
The case study is, even our mental faculty deciding to eat Chicken, Beef or Duck are influenced by variables like belief (have I been told by someone that chicken is delicious?), temperament (my brain subconsciously demands something with delicate texture), etc which are all OUTSIDE our control. And our ‘feelings’ are simply another inevitable cause of those variables.
This claim is backed with scientific evidence. The way our brain sends signals to our organs are influenced by genetic factors, environmental factors (where do you geographically live, the people around you, etc). Until now, no valid rebuttal exists.
This leaves us with an interesting question: If everything in life is inevitably pre-determined, are all our actions (our effort to love someone, our effort to study and win debate competitions) meaningful?
In my opinion, it is still meaningful because those things still influence others positively (you inspire someone, you lift your institution’s reputation, etc.).
But one of the takeaway is, it is principally wrong for anyone to feel superior to the other (being cocky, degrading, etc.) because who you are is NOT influenced, but your free will AT ALL. It is simply luck that you happen to have certain genetics, geographical condition, peers, families, etc. which makes you who you are right now.