Why is Silas Phelps scared?

Silas Phelps is scared because he is deeply concerned about the consequences of harboring a runaway slave, Jim, in a society where such actions are illegal and punishable. His fear is compounded by the potential repercussions from both slave catchers and the law, as well as the moral implications of his actions. Additionally, he worries about the safety of his family and his own reputation within the community.