One of the most known quotes from the horror writer H. P. Lovecraft is
The oldest and strongest emotion of mankind is fear, and the oldest and strongest kind of fear is fear of the unknown. These facts few psychologists will dispute, and their admitted truth must establish for all time the genuineness and dignity of the weirdly horrible tale as a literary form.
from his Supernatural Horror in Literature (1927.) Many people recognize it, and it’s a thought attributed to him even though the next sentence states he thought it was (or wanted to present it as such) common knowledge: “These facts few psychologists will dispute.” He didn’t believe he was discovering anything new.
In any event, I believe I may have stumbled upon Lovecraft’s inspiration for his famous statement.