Final answer:
The quoted statement is the writer's perspective, suggesting that the source making the claim that George Washington is a descendant of Odin is unreliable. The correct answer is option 4.
Step-by-step explanation:
The statement "It is only fair to suppose that Mr. Welles was not in a sound state of mind." represents the perspective of the writer regarding the argument presented in the essay 'George Washington - A Descendant of Odin?' by Yvonne Seale. In the context of such historical analysis, when authors refer to states of mind, it is often to question the credibility or reliability of a historical account or narrative. In this case, the writer appears to be challenging the validity of the claim that George Washington is a descendant of Odin by suggesting that the originator of the statement might not have been thinking rationally.
By touching upon the veneration of George Washington by Americans due to his virtues and the comparison of great figures to natural luminaries, the writer conveys skepticism towards avant-garde historical interpretations, as well as possibly ironic or critical perspectives on historical narratives. Thus, the statement carries an undercurrent of criticism toward historical figures being deified or related to mythological entities, which may distort the true and factual representation of their lives and deeds.