Which word describes speech or writing characterized by strong feelings?

The term that best describes speech or writing characterized by strong feelings is "harangue." A harangue typically involves an aggressive or passionate speech or piece of writing, often directed at an audience with the intention of persuading or strongly expressing a viewpoint. It conveys emotional intensity and is often critical or forceful in nature, making strong appeals to the audience's emotions.

While a rant and a diatribe also express strong feelings, they have different connotations. A rant usually refers to a long, passionate, and often loud speech, but it may not necessarily have the same persuasive intent as a harangue. A diatribe, on the other hand, implies a forceful and bitter criticism against a person or an idea. It highlights the negative feelings but may lack the broader emotional appeal associated with a harangue. Discourse generally refers to formal or informal communication and does not specifically imply strong feelings. Therefore, "harangue" is the most appropriate choice in this context.