病人遭受着残酷和非正义的虐待，他们实际上已经成为了加尼耶的奴隶，但加尼耶仍相信他是在帮助别人。Garnier genuinely believed that he was helping the people that he held in his hospital, despite committing cruel and unjust acts to his patients, turning them into his slaves, and making them his guards. Even though he claimed to be a man of science, he completely lacked a sense of ethics and morality. He did not seem to fear death and even while he was communicating with Altaïr, he attempted to justify his actions, explaining why he dragged them from their supposed "homes" such as [[brothels]] or sewers.
He often wore black robes with an apron that was stained from the blood of the patients who had been involved in his experiments. He had a small leather belt around his waist which held up a small pouch and he usually carried his sword around with him for protection. He was of average height and weight, with signs of aging, such as wrinkles and balding being prominent in his appearance.