There’s a fascinating frailty of the human mind that....

“ There’s a fascinating frailty of the human mind that psychologists know all about, called “argument from ignorance.” This is how it goes. Remember what the “U” stands for in “UFO”? You see lights flashing in the sky. You’ve never seen anything like this before and don’t understand what it is. You say, “It’s a UFO!” The “U” stands for “unidentified.”But then you say, “I don’t know what it is; it must be aliens from outer space, visiting from another planet.” The issue here is that if you don’t know what something is, your interpretation of it should stop immediately. You don’t then say it must be X or Y or Z. That’s argument from ignorance. It’s common. I’m not blaming anybody; it may relate to our burning need to manufacture answers because we feel uncomfortable about being steeped in ignorance. ”

Neil deGrasse Tyson

From : Space Chronicles: Facing the Ultimate Frontier