Final answer:
Belsey and Phillips are concerned about Tom's safety traveling up North due to his possible literacy and exposure to abolitionist ideas.
Step-by-step explanation:
In The Hawk that Dare Not Hunt by Day, Belsey and Phillips disagree with Tom about his safety and the underlying risk of visiting the North, considering his possible ability to read and his exposure to abolitionist ideas. Belsey states the reasons for his concern, highlighting Tom's recent behavior with a newspaper that leads him to believe Tom might have learned to read, which could be dangerous among abolitionists in the North. There's an apparent fear that Tom, being smart and potentially literate, poses a risk if he's taken up North due to the tensions and ideologies prevalent during that historical period.