How can one acquire knowledge through emotions only?

"Knowledge" might be divided into four types: (1) theoretical knowledge (knowing that X); (2) practical knowledge (know how); (3) familiarity (knowing someone); and (4) moral knowledge (knowing what's right). 1. Emotion alone doesn't seem able to produce theoretical knowledge. In fact, emotion often obstructs it. 2. Emotion alone can't make it possible for us to know how to do something--e.g. drive a car or play the violin. But it can be a necessary condition for us knowing how, for example, to play music well or for knowing how to manage people psychologically (as an effective manager, parent, or politician might know how to do). 3. Emotion might be the result of familiarity, but knowing someone isn't made possible by emotion alone. 4. The very idea of moral "knowledge" is a strange one, but one might say that knowing what the right thing to do in a given situation might be said to be determined through feeling. But I doubt it would make sense to say that emotion alone yields moral...