Thufir Hawat is House Atreides’ Mentat, a person who is highly trained in pure mathematics and can advise powerful figures in the most accurate capacity, without the conflict of emotions. Hawat has served the family for three generations, and is extremely loyal, but his old age presents a problem. Paul and his family worry that Hawat is tired and no longer functioning at his highest ability. While Hawat himself would not admit to this, it may partly explain why the Harkonnen Mentat, Piter, was able to construct a perfect scheme to destroy House Atreides without Hawat foreseeing any of his plans. While Hawat was aware that the Harkonnens were laying a trap for House Atreides, he fell for all of Piter’s deceptions – such as believing Lady Jessica was the traitor, thus distracting him from the truth. He did this without considering that someone else might be pulling the strings of his own perception.

The disadvantage of Hawat’s age pales in comparison to the disadvantage of the resources at his disposal. The Harkonnens possessed massive amounts of wealth, allowing them to establish far more lines of information to feed to Piter. Meanwhile, House Atreides did not possess the same extensive resources, so Hawat didn’t receive the same quality or amount of information as Piter. This forced Hawat to make decisions without knowing vital information.

After being captured by the Harkonnens, Hawat serves as the Baron’s new Mentat. His hatred of House Harkonnen persists, despite his new position. He does his best to sow discord between the Baron and Feyd-Rautha by manipulating both of them into his confidence and pitting them against each other. While he hopes the Baron will meet his end, perhaps as the consequence of his own scheming, he mainly focuses on planning the revenge he will take on Jessica for her supposed betrayal. The Baron continues to feed Hawat with false reports of Jessica’s treachery, which Hawat believes, showing once again how vulnerable he is to manipulation. However, while he makes an error in his assessment of Jessica, it is undeniable that Hawat remains loyal to House Atreides until his end. Despite being poisoned, he wills himself to live long enough to repent to Jessica for his mistakes and see Paul one last time.