Fact or Opinion

"Everything we hear is an opinion, not a fact. Everything we see is a perspective, not a truth." -Marcus Aurelius

 What proof do we have that anything we believe to be true is actually true? Every fact we have come to accept, every piece of scientific evidence, every spec of proof, is fragile. Fact has no meaning in relativity to the universe, it is simply speculation. 
Let's say I made the statement that solid objects aren't able to disappear into thin air. I have never seen it happen, nor has anyone else. Science backs up my conclusion. But if one day I witness an object in front of me vanish. What then? My prior beliefs have suddenly become meaningless and false. The idea that objects can't suddenly disappear is my opinion, but there is no way to prove it is truly fact. 
When speaking on the topic of perspective, the same concept applies. The way I see an object or person can never be truth. This is because, no matter how I see it, there will always be someone who see it differently than me. The contradiction of two perspectives destroys all hope of something ever being universally true. The very definition of truth states that it is something "that which is true or in accordance with fact or reality." But the question is, who defines fact? Who defines reality?