"All men profess honesty as long as they can. To believe all men honest would be folly. To believe none so is something worse"

In this quote, John Quincy Adams is highlighting the common propensity for people to declare sincerity and integrity, but only as long as it benefits them. He recommends that blindly thinking all men to be sincere would be absurd, as it is human nature to focus on one's own interests. However, he likewise warns versus the extreme of believing that no one is honest, as this would result in a negative and pessimistic view of humanity. Adams is advising us to be careful and discerning in our trust, but not to despair in the goodness and sincerity of others.