Who said "I can't explain what I've seen, only that I've seen it."?

This quote is attributed to Fox Mulder.

I can't explain what I've seen, only that I've seen it. - Fox Mulder

"I can't explain what I've seen, only that I've seen it."

Fox Mulder Truth

"The truth is out there."

"I want to believe."

"Trust no one."

"The answers are in the questions we're afraid to ask."

"Lucy, you got some 'splainin' to do!"

"You must always be honest with the people you love."

"Truth always comes out in the end."

"Honesty is always the best policy."