T'Hain was a Vulcan writer. The Dictates of Poetics is one of T'Hain's works.

In it, T'Hain says:

"A character's actions must flow inexorably from his or her established traits."

Tuvok quoted T'Hain in 2373 when Tom Paris wanted to make revisions to Tuvok's Insurrection Alpha holoprogram that were at odds with the characters' personalities, such as Kathryn Janeway executing a prisoner. (VOY: "Worst Case Scenario")