Hilda is the first person to question whether the surgery was the right thing to do, and here she establishes one of the novel’s most important themes: the tradeoff between intelligence and happiness. This is essentially what happened in the Biblical story of Adam and Eve—they ate the forbidden fruit of the Tree of Knowledge, and so gained knowledge but lost their innocence and were expelled from Paradise. Hilda’s warning also highlights Charlie as a tragic hero punished for his ambition, and essentially frames the story as a vague retelling of
Frankenstein—man tries to “play God” and is punished for his hubris. At the same time, Hilda’s criticism seems logically biased, as we would assume she wouldn’t object to taking medicine for a sickness instead of just leaving it up to “God’s will.”