"I have met with some of them - very honest fellows, who, with all their stupidity, had a kind of intelligence and an upright good sense, which cannot be the characteristics of fools"

In this quote, Giacomo Casanova is reviewing his encounters with particular individuals whom he refers to as "really sincere fellows." Despite their perceived stupidity, Casanova acknowledges that they have a particular level of intelligence and common sense that can not be attributed to fools. This suggests that Casanova values sincerity and stability above intelligence and acknowledges that these qualities are not equally unique. He also implies that intelligence and common sense are not solely figured out by one's level of education or knowledge, however rather by one's character and moral compass. In general, Casanova's words highlight the importance of honesty and integrity in people, no matter their perceived intelligence.