Final answer:
Paine's line contains parallelism and a metaphor.
Step-by-step explanation:
The quote by Paine, "Mutual fear is the principal link in the chain of mutual love, and woe be to that state that breaks the compact," contains parallelism and a metaphor.
Parallelism
refers to the repetition of similar grammatical structures or patterns within a sentence or across multiple sentences. In this quote, the parallel structure is evident in the phrase "Mutual fear is the principal link in the chain of mutual love."
A metaphor
is a figure of speech that compares two unlike things by saying one thing is another. In this quote, Paine is using the metaphor of "the principal link in the chain of mutual love" to describe the importance of mutual fear in maintaining a harmonious relationship.