Final answer:
The correspondent sets aside his cynical attitude due to growing empathy and compassion towards Bartleby, the scrivener.
Step-by-step explanation:
The most likely reason that the correspondent sets aside his cynical attitude is due to a growing sense of empathy and understanding towards Bartleby, the scrivener. Initially, the correspondent feels pity towards Bartleby's forlornness, but as he witnesses Bartleby's mental and emotional suffering, the correspondent's pity turns into repulsion. The correspondent realizes that Bartleby is a victim of an incurable disorder, and this realization prompts him to set aside his cynical attitude and approach Bartleby with more compassion.