Answer: The italicized part of the sentence, "no one among his own countrymen had been able to interpret Lincoln's greatness more nobly than this Oxford scholar had done, and that vision and wisdom as well as high motives must lie behind every effective stroke in the continuous labor for human equality," could potentially be the thesis for an essay about the influence of Lincoln. This statement highlights the fact that Lincoln was able to inspire others with his greatness and that his actions were driven by a desire for equality.
However, this statement alone may not be a strong enough thesis for an essay about the influence of Lincoln. To fully explore the topic, the essay would need to delve deeper into the specifics of how Lincoln influenced others and the lasting impact of his actions. Additionally, it would be important to consider the broader context in which Lincoln lived and worked, including the political and social climate of the time. Without this broader context, it may be difficult to fully understand the significance of Lincoln's influence.