What is fear?
Its impossible to define any subjective state without a model of consciousness, and Joseph LeDoux's new book Anxious: Using the Brain to Understand and Treat Fear and Anxiety focuses on questions about consciousness a surprising amount.
Conscious and non-conscious states of fear are important. However, LeDoux has a more reified notion of the difference between what is conscious and non-conscious.
I believe that fear is not primarily a conscious feeling. LeDoux believes that the word 'fear' is broadly used to mean a conscious feeling.
He discusses the existence of non-conscious survival responses that are created by deeper parts of the brain. He defines 'fear' as the conscious (primarily neocortical) representation of that survival response.