Usually when we think of emotions we consider them to be single entities. Anger is different from happiness, which is different from boredom, but it doesn’t seem like there are parts to anger or sadness. Appearances can be deceiving though. When thinking about emotions, and our awareness of them, it becomes apparent that what we call an emotion consists of two parts, the feeling and the mood.
The mood, in broad terms, is the changes in our awareness of the world that characterize the emotion. By changes in awareness I don’t mean that when we are angry one objects visually look different than when we are sad, but that how we conceptualize the world changes. When we are afraid things that normally seem indifferent seem threatening, when we are angry these same things are likely to seem annoying, ect. So while the information that represents the physical properties of the world in our experiences remains unchanged the additional “interpretive” information that our mind incorporates into our perceptual experiences is altered. In one sense moods are necessarily conscious, since their effect is to alter conscious experience. On the other hand there is no reason that the person who the mood is affecting will necessarily be aware of its effects, it is possible that they will, but it is also possible that they won’t.
In contrast to moods a feeling is a part of experience that reflects some aspect of mental activity, not necessarily correctly. Just as perception fills experience with information derived from the outside world, a feeling fills experience with information derived from the operations of the mind. If a subject is to be aware that they are being affected by a mood it must be through a feeling, since the effects of a mood, although perception altering, are not themselves part of perception (in the sense that the information that ones perception is being altered is not itself part of perception). Unlike a mood, a feeling is necessarily conscious, since it is defined as being part of an experience. And unlike a mood a feeling has little direct effect on action or perception. At most it allows us to react to our own moods appropriately, so that we can compensate for the effects of the mood if we wish, but the actual act of compensating is not performed by the feeling.
Together, being in a mood and feeling that one is in a mood are what we call an emotion. So why break emotion into these two parts? Well for starters it shows how it is possible to be unaware of an emotion, or mistaken about an emotion, even though the emotion is part of consciousness. We explain such effects by saying that the person is in a certain mood but that the appropriate feeling is missing or misrepresenting the mood. And, when the actual mood we are in is brought to our attention, either by others or by observation of ones own actions, the appropriate feeling manifests as a result of this realization.