Even though Helen seems like she has been stripped of the will to live by Dr. Aftus’s treatments, Benjamin convinces himself the treatments are working and lets Dr. Aftus keep going. Benjamin seems to base his opinion solely on the idea that Helen is engaging
with him more, showing that the sole determining factor in Benjamin’s decisions seems to be his ego. That ego, along with his desire to have power over the situation, then leads to Helen’s death. In that way, Benjamin subjugates Helen to the point that he becomes complicit in her death.