This is one of "22 virus definitions" (thought-mistakes that cause ineffectiveness and unnecessary negative emotions).
A woman I know is afraid of flying. She gets anxious while she is on a plane. When I talked to her about it, she said, "Something bad might happen while we're in the air."
"What makes you think so?" I asked her.
"I feel afraid. The fear is my body warning me of danger." This is an example of using emotions as evidence.
See the complete list of definitions: The 22 Virus Definitions.