"visceral" vs "emotional"
What's is the difference in nuance between visceral (relating to deep inward feelings rather than to the intellect) and emotional?
How do we decide when to use one over the other?
Solution 1:
I think the dictionary definitions you are using are a bit misleading in terms of the way we tend to use these words.
Emotional does not necessarily imply any level of intensity, in my opinion. Rather it indicates that you are referring to something that pertains to the emotions, the feelings, the non-intellectual responses to external stimuli. The intensity of the response may be mild, severe, or anything in between.
Visceral, on the other hand, although it also works on a non-intellectual level, is often regarded almost as if it is not connected with the emotions, because it has the connotation of arising from a physical reaction, commonly called a "gut" reaction, a response one feels typically within the abdominal area (commonly: "the stomach"). This is usually felt to be a more powerful reaction, and so we tend to reserve "visceral" for those reactions which are generated by things that hit us so hard that it almost feels as if we have been punched in the stomach.
Solution 2:
They are definitely in the same semantic wheelhouse. "Visceral" is related to the word "viscera" meaning the inner guts of your body. So it pertains to something that comes from your gut, your body, your physical inner parts.
Emotional, which physiologically relates to various hormones in your blood, refers to things that provoke a set of specifically emotional responses: anger, sadness, love, passion etc.
Perhaps it is best to think of it in a hierarchy, the degree to which reason plays a role in the action. Consider for example a decision being made by a person, perhaps a woman is trying to decide whether to marry a man.
At the top she might make a rational decision: are we compatible in interests, are our careers compatible, do we have the same goals.
At a second less rational, but still somewhat reasoned level, emotional, she might consider her feelings toward him -- does she have affection for him, does she love him, how does he make her feel?
At a third, even less rational level is her visceral level, is she intensely sexually attracted to him, does she just feel a passion in her gut for him. Not love, but purely from her body. It is her gut, her inner animal, her non rational, non emotional physical reaction.