Imperial Conditioning was a development of the Suk Medical Schools. It was the highest conditioning against taking human life, which meant that a Suk Doctor who had this conditioning could even serve an Emperor.
Initiates were marked by a diamond tattoo on the forehead and were permitted to wear their hair long and bound by a silver Suk ring.
The conditioning against taking human life had remained a stalwart of the Suk school for millennia. However, a way was found by House Harkonnen agent Piter de Vries to break this conditioning. De Vries realised that a person, even a Suk doctor, could be made to do another's bidding if one of their loved ones was held hostage. In this way, he was able to control Wellington Yueh into betraying his Duke, Leto Atreides, and deliver him to Baron Vladimir Harkonnen.
Though Suk Doctors continued to exist even into the time of Leto Atreides II and later amongst The Scattering, it could be surmised that the Suk School lost much of its prestige from this time onward or that their Conditioning was considered ineffective at the very least.
Behind the ScenesEdit
Most adaptions fall short in explaining how exactly de Vries managed to break Yueh's imperial conditioning and simply rely on him being blackmailed by the Harkonnens, however the very point of imperial conditioning was to make such manipulation by blackmail, bribery or pressure all but impossible. Even in the book itself it is indicated that de Vries or at least the Baron, himself was not fully aware on how they had managed to overwrite Yueh's conditioning. De Vries seems to have created a necessity for Baron Harkonnen's death in Yueh's mind, however as Yueh's own conditioning prevented him from doing so by himself, De Vries' counter-conditioning pressed Yueh into a situation in which the death of Baron Harkonnen by the hands of another needed to be arranged -this other however could be none else but Duke Leto. In a way in this counter-conditioning the treason on Leto was just a by-product and the necessity of Leto's death to bring forth Baron Harkonnen's death enabled Yueh to overcome his original conditioning and commit treason. De Vries had used the Baron himself as means to transmit Yueh's conditioning against killing into a conditioning of the need to arrange the circumstances of a target's certain death -a fact De Vries never had openly revealed to his master.