Why switch from Bilbo as protagonist at all? Christopher Tolkien quotes JRR's biographer Humphrey Carpenter saying that JRR felt further adventures of Bilbo were incompatible with how he'd been left at the end of The Hobbit, and that he (JRR) had explored most of the possiblilities of Bilbo's character. Christopher Tolkien calls this 'plausible'. Interesting, perhaps that JRR felt he needed a new character (meaning someone with a new personality, I assume) to write about before it was at all clear what advetures this person was to be involved in.

Why can't the new hobbit protagonist be Bilbo's son (or other direct descendent)? Commenting on 'Version 4' Christpher Tolkien says "Bilbo's marriage (as was inevitable, I think) has been rejected".
He does not say why he felt that was inevitable.

Tolkien sticks with the new protagonist being Bilbo's heir though. So we end up with with Bilbo needing an adopted heir (who will then presumably have to have been orphaned before that). Tough on poor Primula: like Merry's ponies, she never got to Rivendell .

What does this bring to the new story? A few ideas, please add:

• Frodo is an orphan (like JRR Tolkien: co-incidence or important?)
• Frodo continues the Baggins reputation for 'oddness'. That gives us a point of view character (and narrator, if one goes for the Red Book of Westmarch idea) who is a hobbit, but can observe hobbit society and customs as somewhat an outsider. And, perhaps, who is not fully satisfied by life in The Shire, and so is open to being cosmopolitan and going adventuring. I think it might have been that perspective - looking at society while feeling a bit alienated from it - that resonated with me in my early pre-teen and teen readings of the book. I've heard that it resonates in a different way with Bilbo and Frodo's many LGBTQI+ fans, and that understandably leads to a 'queer' reading of our hobbit heroes. I also think it's possible that JRR was a bit of an outsider himself in several ways- orphaned; of a minority religion against which prejudice could certainly have been encountered; a nerdy kid in a school that emphasiesd sports (though thank goodness he found some talent at the game of rugby). Later, a returning combat veteran; and although that was a common experience for a time, there were plenty enough people to stare rather than understand if a man hit still instinctively hit the deck if a car backfired (or other ongoing symptoms of wartime trauma). Still later, landing a prestigious Professorship and then becoming best-known as a childrens' author: odd again. Has Tolkien given himself some scope to explore a few things in fiction? Does he give his readers some scope to explore a few things?
• Part of the 'oddness' is unattachedness. Neither Baggins has to say farewell to a wife left at home (as 2nd Lt Tolkien did). Or to children. Is that a relief to the author? Or does Bilbo start out unattached because (squire's idea, I think) he is a children's book character and is a child's idea of playing grown-ups: freedom and agency, but no work or family commitments (and then does that carry on to Frodo)?
• Frodo is a much more reluctant adventurer than Bilbo, leaving the Shire much more from necessity and duty than from a wish to have adventures. And of course his quest is clearly going to be No Fun At All.

Frodo is a more emotional and sensitive hero suitable for a more emotionally complex and serious story. Frodo is written like a female character in some ways, really, demonstrating patient endurance and interpersonal skills and resisting temptation rather than doing normal heroic feats. Bilbo is much closer to the normal male action hero, only lacking in the physical prowess and the skills, so he needs a magic ring to even the odds.

One of the great problems in the world today is undoubtedly this problem of not being able to talk to scientists, because we don't understand science. They can't talk to us because they don't understand anything else, poor dears. This problem, I think it was C.P. Snow first raised it - Sir Charles Snow in private life - in his books Science and Government and so on. Mind you, I haven't read it. I'm waiting for the play to come.

He says, quite rightly, he says it's no good going up to a scientist and saying to him as you would to anybody else, you know, "good morning, how are you, lend me a quid" and so on, I mean he'll just glare at you or make a rude retort or something. No, you have to speak to him in language that he'll understand. I mean you go up to him and say something like, "Ah, H2SO4 Professor! Don't synthesize anything I wouldn't synthesize. Oh, and the reciprocal of pi to your good wife." Now, this he will understand.

Snow says that nobody can consider themselves educated who doesn't know at least the basic language of science. I mean things like Sir Edward Boyle's Law, for example - the greater the external pressure, the greater the volume of hot air. The simple . . . or . . . the Second Law of Thermodynamics, this is very important. I wasn't so much shocked the other day to discover that my partner not only doesn't know the Second Law, he doesn't even know the First Law of Thermodynamics!


Going back to first principles, very briefly: thermodynamics, of course, is derived from two Greek words, thermos, meaning hot - if you don't drop it - and dynamics, meaning dynamic, work; and thermodynamics is simply the science of heat and work, and the relationships between the two as laid down in the Laws of Thermodynamics, which may be expressed in the following simple terms - after me, Donald...


Intro to 'First and Second Law of Thermodynamics' (1964)

I find it difficult to believe this, yet if it is not so the coincidence is strange. If Bingo Baggins did get his name from this source, I can only suppose that the demonic character (composed of monomaniac religious despotism and a lust for destruction through high explosive) of the chief Bingo (not to mention that of his appalling wife), by which my sister and I now remember them, developed somewhat later.