T'Plana-Hath was an ancient Vulcan known as "Matron of Vulcan Philosophy". One of her commonly quoted sayings is, "Logic is the cement of our civilization, with which we ascend from chaos, using reason as our guide." (Star Trek IV: The Voyage Home; ENT: "The Forge")

Years later, the Vulcan High Command would name vessels after the philosopher in homage; such as the T'Plana-Hath, a landing craft. (Star Trek: First Contact)