Symbolism, Imagery, Allegory
Throughout the Enquiry, Hume sketches out a whole list of qualities that make someone a model citizen. This person should be loyal and caring toward those closest to them while also showing compassion toward human beings in general. They should spend their time and energy on tasks that are useful and agreeable to society but they should have a healthy amount of self-interest too. They shouldn't be arrogant, devious, or foolish; instead, they should display modesty, honesty, and stick to their principles. Some list, huh?
Hume emphasizes that some qualities are so vital that possessing them isn't something to be celebrated—it's taken for granted that people should be polite and pleasant. We don't expect a medal for basic decency; it's when we're lacking this that we open ourselves up to criticism.
There are other virtues that aren't expected of everybody and are all the more valued because of their rarity. We can't all be J.K. Rowling or Stephen Hawking, but that's okay: Hume's more realistic about the everyday virtues that matter.
We might feel as though we don't live up to Hume's vision of the ideal citizen, but when a writer/philosopher is making a point, it's often most effective to compare polar opposites. That's the approach Hume takes here, and his aim isn't to make us feel as though we're not good enough—it's to give clear examples that help us understand his theory.