First of all, many researchers separate feeling and emotion, where feeling is the subjective experience of the emotion. Some believe that emotions happen unconsciously, and hence that emotion is a much more general phenomenon than its subjective feeling. Feelings may also refer to the experience of bodily changes.

Some theorists argue that some emotions can be caused without any thoughts at all. They point immediate reactions. Debate on this point represents a major distinction between what are called cognitive theories and non cognitive theories of emotions. Non cognitive theories regard bodily responses to be essential.

A second distinction focuses on the separation between the emotion and the emotion's cause. For instance, do we say that thoughts about a loved person cause the emotion of love or that these thoughts are part of the emotion? To resolve this, a good way is to see whether the emotion occurs independently of these thoughts. Thoughts about a particular person or situation could not be part of the love emotion, since one can experience that same emotion about many other things. One could yet experience love without some thought of a loved person or object? If not, then we may stipulate that thoughts of a loved object are part of the emotion.