@Didymos Thomas,
Yeah, I've skimmed through Hume before. His writings, compared with Locke, I find to be shallow and boring, and the whole general tone of his writing is just annoying to me. Take this paragraph as an example, from An Enquiry Concerning the Principle of Morals, Section IX, Part I:
And as every quality which is useful or agreeable to ourselves or others is, in common life, allowed to be a part of personal merit; so no other will ever be received, where men judge of things by their natural, unprejudiced reason, without the delusive glosses of superstition and false religion. Celibacy, fasting, penance, mortification, self-denial, humility, silence, solitude, and the whole train of monkish virtues; for what reason are they everywhere rejected by men of sense, but because they serve to no manner of purpose; neither advance a man's fortune in the world, nor render him a more valuable member of society; neither qualify him for the entertainment of company, nor increase his power of self-enjoyment? We observe, on the contrary, that they cross all these desirable ends; stupify the understanding and harden the heart, obscure the fancy and sour the temper. We justly, therefore, transfer them to the opposite column, and place them in the catalogue of vices; nor has any superstition force sufficient among men of the world, to pervert entirely these natural sentiments. A gloomy, hair-brained enthusiast, after his death, may have a place in the calendar; but will scarcely ever be admitted, when alive, into intimacy and society, except by those who are as delirious and dismal as himself.
More particularly, let's look one-by-one at the qualities of the second sentence.
Celibacy--True, avoiding sex doesn't lead to virtue, but imo there is something akin to sex, namely sodomy, that is addictive. Even if one doesn't believe that, one can't have much refined sentiment or whatever or much familiarity with the real world without recognizing that skankiness and sexual depravity aren't just social constructs or whatever caused by superstition or (to use modern the modern cliche) patriarchal gender stereotypes. Women (and men too, though less often, since bad males tend to prefer enslaving females, and only males can sodomize) sometimes have become skanks, I'm sorry.
Fasting--We are what we eat. Obviously fasting to extremes is silly, but probably there is nothing one can do more to improve the sacredness of one's life than to eat in moderation the right food. And eating in moderation is akin to fasting. Locke wouldn't demean those with fasting instinct. On the contrary, Locke was so self-disciplined when it came to eating that he felt people should not eat during the day before supper. Apparently, he fasted most every day, sort of.
Penance--Penance is a wonderful thing. Screwed-up people can make their rescuers obsessed with rescuing them. It is a great good for them after having reformed to undergo the penance of giving their rescuers some idea that they are not needed. In particular, if a reformed female does not desire a male who rescued her or tried to rescue her, she ought to be so polite as to make at least a small effort to convince him that her not desiring him is not on account of her still being screwed-up. This is probably why in fairy tales rescued damsels are always nice to heroes who rescue them even beyond the demands of gratitude; it's an important trait to inculcate, for in reality a rescued female will feel so embarrassed that if she didn't feel the penance instinct she would nevertheless, to avoid the embarrassment and shame, avoid her rescuer, even at the risk of his mentally tilting at windmills forever trying to slay the dragon that he doesn't know doesn't imprison his beloved anymore.
Mortification--Withdrawals from addiction are mortifications that are appropriate.
Self-denial--Does he mean unselfishness or mortification? Either way, they have their virtues.
Humility--Feeling pride in the wrong things and feeling shame in the wrong things--you can't have one without the other because they are basically just two sides of the same coin. Pomposity leads to duels, etc., and nothing agreeable about those. Also, a too general belief in the importance of pride, and you've got Hollywood morals. It makes one wonder whether that's why Hume became popular to begin with--he knew how to smile and clap in just the right way, the way the "right" people do at the Academy Awards of our day. Only, philosophers have a choice; I'm guessing you don't really have a choice if you want to work in Hollywood.
Silence--Music has addictive qualities, as should seem clear to those who have ever been annoyed by a catchy song that yet is ugly. Personally, I like about 99.8% silence over music.
Solitude--The most failsafe way of judging others, if you are actually concerned about being just, is to see how well they judge you. And finding yourself is also particularly virtuous because it necessarily must be your employment if you wish to behave according to your own special qualities, tendencies and beliefs, all of which won't evolve well to help humanity if people just ignore them, deciding in stead to behave and believe according to some typical belief system. And solitude helps you to find yourself (though much of ourselves is how we relate to others; for instance, people can't probably understand their sexual selves without having some acquaintance with the opposite sex, but even there solitude is useful and preferable unless one wants a world where people masturbate in public, nah). Locke, on the other hand, emphasized the importance of thinking for oneself and of reflection--perceiving the operations of one's own mind as it operates--which I daresay one can most easily do in silent solitude.
I am not saying that there isn't something often insane about monkish extremes such as eschewing sex, but Hume doesn't seem to admit to there being anything useful or agreeable about the emotions that can lead to those extremes. He seems fanatically in favor of undiscipline. The truth is one does not need to be so afraid of throwing out the baby with the bath water as to argue that wanting to bathe the baby is hair-brained. Is there something particular in Hume's philosophy that you find especially ingenious or profound? I could examine that and see whether I find it profound. Vaguely, I suspect that the greatest harm arising from his philosophy is that it encouraged excess disrespect for subjective belief (or another way to put it, he encouraged people to respect sensation over what Locke calls reflection), though I don't have sufficient familiarity with his writings for it to be more than an educated guess.