When I teach introductory level courses in philosophy, it is my habit to use complete primary texts whenever possible. For example, this term I am teaching Philosophy 101 and so far we have read Plato's Gorgias in its entirety; Plato's Theaetetus in its entirety; most of Aristotle's Metaphysics, David Hume's Dialogues Concerning Natural Religion, again in its entirety, and all but one section of Nietzsche's Beyond Good and Evil. Although that's a lot of reading, it is a lot of very good reading, and my hope is that my students will be better off in some way for having read these books, whether or not they get the grade they were hoping for in my class.
Most of those writers are not only good philosophers, but fine writers as well. (In all truth, I would say that really only two of them are good philosophers, and three of them are fine writers. Your homework: figure out which ones are which.) Plato, of course, was in antiquity and remains to this day justly famous for being not only one of the greatest philosophers of all times, but also for his unparalleled Greek style. Indeed, one should really say "Greek styles", because in many instances his command of the various mannerisms and modes of speech employed by the various historical characters he puts into his dialogues is quite impressive. His dialogue Symposium is a case in point: the characters in that dialogue are all historical persons, each with his own style of speaking and particular world-view, and Plato captures the differences without seeming forced or artificial.
Aristotle, by contrast, will probably not win any creative writing awards any time soon, in spite of the fact that he is, in my own humble opinion, the greatest philosopher who has ever lived. To be fair, he did write philosophical dialogues similar to the ones Plato has left to us, but they have all been lost. It would be interesting to have a look at one of them--ancient reports have it that they were really quite good.
When teaching Plato and Aristotle to undergraduates, of course, one almost always must teach them in English translation, and that is rather unfortunate, because every translation is also an interpretation, and not all translators are equally up to the task.
This is not a problem with the writings of David Hume, of course, because English was his native language, and I would say that of all philosophers writing in English his philosophical prose style is the best. (Willard Van Orman Quine, the 20th century American philosopher, also writes very well, but I would make him a distant second to Hume.) In some ways this can be a problem for some undergraduates because they aren't always the very best readers (in fact, our incoming freshman class this year has the poorest reading skills of any class since 1993). Plato and Aristotle, of course, are in translation, and the translations are usually made just for the college crowd. Hume is speaking sua voce, as it were, and so there's no "translator" acting as a middleman to re-render his prose into something that a college aged reader (that is, someone who can read as well as an eighth grader could in my mother's day) can handle.
As a writer, then, Hume is unequalled in English language philosophy (well, in my opinion). Philosophically, however, just about every English language philosopher (and most of the others, too--well, except maybe for those French guys) has written better stuff than Hume. David Hume is the philosophical equivalent of a one-hit wonder, an intellectual version of The Rembrandts. (They wrote the theme to the TV show Friends, in case you've never even heard their one hit.) He managed to parlay two or three pretty interesting ideas into hundreds and hundreds of pages of wonderful prose. But if you're looking for powerful and persuasive arguments, you're out of luck.
A case in point that happens to be fresh in my mind, since I've just finished teaching it in my introductory philosophy class, is his postumous essay On Immortality. Hume argues against the widely held view (at least among Christians) that the soul is immortal by raising a series of questions designed to call into question the plausibility, not of the soul's existence per se (as an empiricist he cannot reasonbly claim to know that there is no such thing), but the soul's property of being undying. In this regard he makes several metaphysical arguments that are of varying quality. He adds to these metaphysical arguments, however, some moral considerations that are of very low quality because they are grounded on a very poor understanding of the nature of Christian theology--the very theology, in fact, at which his argument is aimed.
When I was living in North Carolina I used to see an old flatbed pickup truck driving around the streets of Chapel Hill with a large painted sign in the back. On one side of the sign were the words "Hell is hot"; on the other side the words "Eternity is long". This seems to have been about the extent of Hume's understanding of the Christian teaching on heaven and hell. For him, as for many Protestants, I imagine, heaven and hell are all about rewards and punishments. If you live a good life, you go to heaven; if you live a bad life you go to hell. And you go to these places as a consequence of the way you live your life. It is not difficult to see why people, especially people like Hume, might draw the inference that heaven is a reward for right living, hell a punishment for wrong living. Hume's argument amounts to the claim that eternal punishment or reward is never going to be fitting for the sorts of lives that ordinary human beings lead, and so the whole doctrine is manifestly unjust.
But this way of looking at heaven and hell is worse than useless--it's downright dangerous. It is not wholly wrong to view heaven and hell as destinations of a certain sort that one arrives at as a "consequence" of living in a certain way, but one must understand what kind of consequence we're talking about. Suppose you're a huge football fan living here in Athens, Ohio, and you want to go see the Pro Football Hall of Fame up in Canton. So you ask me: "How do I get to the Pro Football Hall of Fame?" I say: "If you want to get to the Pro Football Hall of Fame, you have to take 50 over to Marietta, get onto I-77 and head north for about three hours. You'll see it on your left soon after getting into Canton."
OK, so you head out in your car and you drive to Marietta then up to Canton, and you arrive at the Hall of Fame. In a certain sense it is true to say that you arrived at the Hall of Fame as a "consequence" of your driving on the right roads and going in the right direction, but who on earth would think of the actual arrival at the Hall of Fame as a reward for having driven in the right direction? It's not a reward for the particular route you took, even though it is a consequence of that route. If seeing the Hall of Fame is a reward for anything (IF, mind you) it is a reward for your wanting to see it so badly, not for your driving your car in a certain direction. Our goal in life is to love God, and just as there really is only one right way to get to Canton from Athens, there is only one right way to love God--the way that God himself wills and teaches through the Magisterium. If what you want is to love God in the right way--and that is the natural end of man--then you must do what God wills and teaches through the Magisterium. And if you love God in that way, you will find yourself quite close to God--so close, in fact, that when your earthly sojourn is over you will find yourself contemplating the Beatific Vision. That state will, in a sense, be a "consequence" of the life you have lived, but it is not a reward for having lived that way. After all, we don't ordinarily reward someone for doing something that they are supposed to be doing. When I drive at the proper speed on my trip to Canton I do not get any rewards, and I can't get any rewards by threatening to drive faster and faster until somebody starts paying me some money to slow down. Trust me on that one, I've tried it.
"Ah," you might be ready to object, "but if you drive too fast you will get a ticket and that ticket will be a punishment for what you are doing and not a mere consequence." Possibly, but going to hell is not a punishment for living wrongly, but rather is a mere consequence, since it is not so much like speeding on the highway as it is like turning south instead of north at Marietta on the way to the Hall of Fame. You're heading in the wrong direction, away from God and what he wills for us, and hell is not a fine but a state of your soul in which you suffer the loss of the Beatific Vision. To say that it is not a punishment is not to say that it is not unpleasant. There will be wailing and gnashing of teeth, after all. But the temptation is to see that wailing and gnashing of teeth as somehow retributive in nature, a corporal punishment inflicted on us by God, rather than as a state we bring on ourselves by turning away from God. But we already know that God does not will the loss of any sinner or the suffering of any person. So if we are lost and we do suffer it is not because of anything God does to us but because of a deliberately wrong turn that we ourselves have made away from God.
That this distinction is lost on someone like Hume is not surprising, really, given his background and given his level of interest in finding out what the faith really teaches. For him all religion is "arrogant bigotry and superstition," and his attacks against Christianity in particular show that he is not so much interested in understanding the religion as he is in bringing it down. (We can see the same attitude in his self-professed followers these days--folks like Simon Blackburn proudly call themselves "Humean" in their orientation.) I have often had a certain sympathy towards the view sometimes known as "universalism", and I may post on the topic later, but I do believe that, in the case of folks like Hume, wherever they end up, in the end, will be a consequence of--though not a punishment for--the way they formed their conscience in this life.