Jubal Harshaw is introduced as "Jubal E. Harshaw, LL.B, M.D., Sc.D., bon vivant, gourmet, sybarite, popular author extraordinary, and neo-pessimist philosopher" (10.1). And, yeah, that's Jubal. See you at the next character analysis. What, you say you need more? Um, okay, we guess there's more to consider.
Jubal has christened his home "Freedom Hall" (10.71) in the same way a captain would christen his ship. He does this because freedom, or more specifically individual liberty, is what Jubal is all about.
Jubal believes that everybody should be mainly responsible for themselves and their own happiness. As he tells Jill, "of all the nonsense that twists the world, the concept of 'altruism' is the worst. People do what they want to do, every time" (24.17). Seems he's been reading a little too much Ayn Rand.
This isn't to say that Jubal doesn't believe in helping people; after all, he helps Jill and Mike in their time of need. Instead, he just won't help anybody unless it's what he wants to do, and he doesn't "serve humanity" (10.95) simply for the sake of being a useful citizen. For Jubal, being a useful citizen means doing what Jubal wants to do.
You'd think this means that Jubal is against government. After all, governments create laws and rules, and these laws and rules can sometimes limit a person's freedom. Well, yes and no. As Jubal tells Ben, he finds "[d]emocracy [to be] a poor system; the only thing that can be said for it is that it's eight times as good as any other method" (18.34). So, he's neither for nor against government. Instead, Jubal supports laws that protect individual liberty but is against those that limit it. In fact, the entire second part of the book is basically Jubal lawyering up on the government, specifically Joe Douglas. He doesn't want to overthrow or beat the government; he simply wants to ensure Mike's liberty and freedom.
Jubal's single-minded pursuit of freedom and liberty goes a long way. In fact, this attitude is part of what influences Mike to develop his Church of All Worlds. No Jubal, no Church. No Church, no killed-by-a-mob ending. As we see, Mike's church becomes his own Freedom Hall with its free sexual congress, nudism, and bowls full of money that members can dip into. Mike kind of takes Jubal's freedom idea and runs with it to the nth degree.
Okay, maybe terrorist is a bit strong as a metaphor, but we wouldn't want to go toe-to-toe with Jubal in a debate. On any subject. Ever.
You might notice that most Jubal chapters consist of him sitting down with someone and talking with them. (Exciting!) More specifically, he listens to the person discuss their problems with a particular social institution or custom. Duke talks with Jubal about his dislike of Mike's cannibalism, Jill considers Fosterism with him, and Ben discusses his disgust with Mike's sexual practices.
In each instance, Jubal listens and questions the person about why they feel the way they do. (Was PsyD one of his degrees?) He then digs into his vast knowledge of various subjects to provide the other person with a context they might not have previously considered. This ability allows him to see beyond the "common sense" of cultural custom and tradition. In other words, this dude is open minded.
Jubal is a source of wisdom for the characters—he's the philosopher of the novel. In fact, Jubal's rhetorical method is very similar to the Socratic method. Only, Socrates had a far lighter touch; Jubal just tells it like it is.
While Mike never picks up the rhetorical abilities of his mentor, he does admire them. He believes that Jubal's rhetorical ways allow him to grok in fullness without having to learn the Martian language. The result? Mike makes Jubal the patron saint of his Church of All Worlds. Not too shabby.
Jubal considers himself to be the proverbial old dog that can't learn new tricks. All this, despite the fact that he helps most of the other characters grow throughout the novel. He won't kiss any of the young women in his house, even when propositioned, and when Mike says he'll teach Jubal the Martian language, Jubal warns him he "may have arrived fifty years too late" (12.219).
But when he goes to Mike's church toward the novel's end, things begin to change. Jubal accepts the seduction of Dawn Ardent. And after a brief suicide attempt, he realizes the error of his ways and opens up his home to anyone in the Nest who wants to stay with him. Bottom line: he begins accepting his place in Mike's new culture.
So, has Jubal grown? Has the pillar of everyone else's wisdom begun to learn something new? Well, it's kind of left ambiguous as to how much of an impact Mike's ideas had on Jubal. Of course, considering Jubal's stubbornness, any change is really a phenomenal success.