Question

I’ll define the concepts more clearly as I understand them, and maybe that’s where my mistake is.
Cause — it is what brings something about. That is, everything that exists or happens has a cause that compels it. The cause, of course, fully compels it and compels it to be exactly as it is or as it happened.
Free choice — there is a possibility of stepping outside the circle of circumstances/causality, meaning stepping outside the necessity of causation in certain situations.
Purpose — it is the motivation from which the chain of causes is created. For example, a person who goes to buy food: the purpose is his desire to eat, and it creates a chain of going to the store, buying food, paying, and then eating. The purpose creates the chain of causes, but of course the purpose also has a cause — that is, there is a reason why a person wants to eat.
So the question is: obviously there is some factor operating in a person, but still that factor does not compel the result. If the claim of free choice is that there is an additional component in a person — and for the sake of discussion we’ll define it as the component of the soul — that enables a person to create a cause by choice, meaning to create a cause that has no cause compelling it, I can understand that, and of course it can’t be proven. But I don’t understand what the concept of purpose adds. After all, purpose is a person’s final desire, and that too stems from a cause. If so, purpose too is a circumstantial/causal product. So what have we gained, and what is a purpose without a cause? In short, to say “purpose without a cause” is to say “cause without a cause,” because the concept of purpose too can be subjected to the question: does it have a cause, or is it random?
In short, as you can probably tell, I’m a bit confused and not managing to fully grasp the point.