To underline or not, is the foggy question for many when dealing with direct thought. I'm not sure how this quandary started, or even where, but I do know when I turn a page of someone's manuscript, my eyes wander to the underlined words. Basically underlining throws me out of the story, my mind is now wondering what is so important it must be underlined. When I finally reach said underlined words, I'm practially shouting the phrase in my mind. And that, is rarely what the author had intended the reader to do.
So why do writers underline the direct thoughts of their characters? The first valid reason is a publishing house may prefer to see direct thought underlined so type setters can catch these groupings and transfer them to italics for the book. I can accept that. I also understand standards change over time. And the last time I was in school, granted it was post Dark Ages era, I may have missed out on the importance of underlining direct thoughts of my characters. I like to think I would have rebelled at doing such a unsavory thing.
Using he thought is more preferable for me, or some variation of relaying the thought process to the reader. Direct thought is merely unspoken dialogue, and it's okay to assume your readers are intelligent enough to understand the thinking process going on with your character.
Others use italics to convey direct thought. This is much less distracting while reading and eliminates the need to say he thought/she thought. Still others rely more heavily on indirect thought, or a summary of the character's thoughts through narrative.
How you convey your character's insight and internal conflict can be tricky, but as an avid reader I caution those who lean to heavily on one way over the other. Seeing the page riddled with italics or underlined words becomes intrusive to the story. If your manuscript looks heavy with too many direct thought patches, consider rewording to create a smoother read with more indirect thought.
Let us know how you decide on direct vs. indirect thought with your characters.
Til next time ~