Here are two quotes from the story:
"Melanctha Herbert always loved too hard and much too often. She was always full with mystery and subtle movements and denials and vague distrusts and complicated disillusions."
“Yes I certainly do understand you when you talk so Dr. Campbell. I certainly do understand now what you mean by what you was always saying to me. I certainly do understand Dr. Campbell that you mean you don’t believe it’s right to love anybody....I mean real, strong, hot love Dr. Campbell, that makes you do anything for somebody that loves you.”
Melanctha wanted to love, but she was afraid of it. She was afraid that love would cause her to lose her courage and her strength, because as the second quote says, love can make you do anything. She fears love, but she wants it as well.
Read the enotes sections on characters and themes for more on this topic. The links are below.