The statement that best describes the ways the speakers in "A Thought on the Inestimable Blessing of Reason" and "Deliverance From Another Sore Fit" achieve contentment is:
In “A Thought . . .,” the speaker achieves contentment through rational thought, while in “Deliverance . . .,” the speaker achieves contentment through religious faith.
This accurately captures the differing approaches to contentment between the two works, highlighting the emphasis on reason in the first and faith in the second.