Three important concepts: probability, belief, and proof
Proof
Use in strong sense100% probable.
Rarely prove anything.
Instead, we believe.
Belief
Believing is establishing a threshold of probability above which we will accept an idea as true (arbitrarily raise its probability to 100%).
In the law, convicting is believing, not proving.
In the JFK assassination, we must prove, not believe.
Doing this creates a whole new world where everything is different from before.
We can prove very few ideas. Most we either reject or retain.
If we use proof in weaker senses, confusion reigns.