Here's our recipe for Arthur Dent: Take one hero. Now remove everything heroic. Voilà: You've just made Arthur Dent.
Okay, that's a little harsh, but only a little. If this were a book by almost any other science fiction author, Arthur Dent would either fight off the alien invasion; or discover a way to use the Improbability Drive to save the world; or even just get romantically involved with Trillian. But what we get here is a protagonist who mostly wanders around in a confused daze and gets things explained to him.
It's not just the shock of having his world destroyed that makes Arthur such a terrible hero. We know Arthur has pretty much always been this way, because we've seen just how he dealt with the crisis of the bypass going through his house. In Chapter 1, we hear how Arthur has spent his Wednesday night: "He vaguely remembered being angry, angry about something that seemed important. […] Something about a new bypass he had just found out about. […] It would sort itself out" (1.14). So Arthur has discovered that his house will be knocked down and his response is to (a) get drunk, (b) complain about it, and (c) assume that the issue will clear itself up without his action.
Arthur does do some heroic acts: he lies down in front of a bulldozer (1.16); he improvises some poetic appreciation for Prostetnic Vogon Jeltz (7.18); and he turns on the Infinite Improbability Drive, which saves them all from the missiles launched by Magrathea (17.95). But in all of those cases, Arthur only acts at the last minute, when there's no other hope for survival. In the face of danger, Arthur doesn't jump up to save himself and others; mostly, he just says something like "So this is it, we're going to die" (7.117 and, in slightly different form, 17.89).
We'd like to point out, by the way, that even though it's not clear in the book what Arthur is wearing, in the TV show, they show him wearing his morning bathrobe—for the whole show. We're totally behind that costuming decision. Can't you just see Arthur spending all his time in a bathrobe, not dressed at all properly for an adventure? He just wants to go home and drink tea, not go off and save the universe. The lesson to us here is clear: dress every day as if the world is going to be destroyed that day and you're going to wander around the galaxy in those clothes.
Don't get us wrong, though. We kind of like Arthur, even if he is an unheroic doofus who wanders around in a perpetual daze not really knowing what's going on. Why do we like him?
Well, even though he's not heroic, and even though he pretty much just panics when faced with danger, Arthur still sometimes finds humor in these terrible, deadly, no-good situations. For instance, when Ford first tells him that they are safe on an alien ship, Arthur responds "this is obviously some strange usage of the word safe that I wasn't previously aware of" (5.25). He could freak out there (aliens, ships, ah!), but he just calmly and ironically points out that Ford is using the word in a strange way. Arthur shows us the absurdity and humor in these awful situations, and it's like he's saying, "Hey, don't despair. Laugh instead."
Similarly, when Slartibartfast starts telling Arthur all about how Earth was a computer ordered by mice, Arthur doesn't freak out. In fact, Arthur makes a little joke about how he should be freaking out but isn't when he says, "would it save you a lot of time if I just gave up and went mad now?" (24.45). Presented with a situation that should drive him seriously mad. or at least make him want to drown his confusion in Pop Idol competitions, Arthur is cool enough to make a joke about it.
In some of these situations, Arthur knows that he's not safe (on the Vogon ship) or that he might go mad (with Slartibartfast). But he's not giving in to panic and despair. He's deflecting it with a little humor. Arthur expresses the spirit of the book better than almost any other character: rather than break down crying over the disasters he faces on a regular basis (though he does that too, once or twice), Arthur is most likely to look for tea (unsuccessfully) and note how messed up this whole universe is.
We probably don't want to be just like Arthur Dent, but he is an easy character to relate to. He's the guy who doesn't know what's going on—just like we don't know what's going on—unless you did know that Earth was a computer paid for by mice, in which case you might want to talk about that to your doctor. Everyone has to explain things to Arthur, and that means they explain things to us. For a terrible afternoon project, imagine what this book would be like without any Earth-people—just Zaphod and Ford planning to explore Magrathea. They wouldn't have to explain anything to us and would probably just spend their time drinking.
It's true, folks: in an early pitch for the radio show, this character was going to be called Aleric B. You can see a copy of that pitch, with "Aleric B." crossed off and "Arthur Dent" penciled in, in Don't Panic, the guide to Hitchhiker's Guide
Thankfully, they changed the name. Arthur Dent is totally the better name for this character. "Arthur" is a lot plainer and more common—it's the 82nd most common name in Britain today—than "Aleric," which sounds a little exotic and exciting. And since this guy is plain, the plain name is better.
"Dent" is nice because it's plain, too, and on top of that, it sounds like something that has been damaged. And, well, that's kind of the story of Arthur's life here: his house is "dented" by the bulldozer; and then his planet is, ahem, dented by the Vogons; and by the end of the book, the mice want to "dent" his brain by chopping it up. So Arthur is always trying to avoid some "denting."