The passage establishes a distinction between two types of fear: Fear: A reaction that is proportionate to the danger (e.g., a mother's fear when a child has a serious illness). Anxiety: A reaction that is disproportionate (gap 20) to the danger, or a reaction to a danger that is not real or present. The second part of the distinction is what fills the gap. This term must describe a danger that is not real or immediately present. The word "imaginary" means non-existent; existing only in the mind.