In a review of the recent Thomas Pynchon novel in the March 5, 2007 issue of The New Republic (available online here), literary critic James Wood begins by asserting:
Broadly speaking, there are two great currents in the novel: one flows from Richardson and the other from Fielding.
Samuel Richardson (1689-1761) and Henry Fielding (1707-1754) were literary rivals as well as seminal figures in the development of the English novel. Fielding, best known today for the bawdy comic novel Tom Jones (1749), is described in Wood's dichotomy like this:
Fielding belongs to the theater. His characters vibrate vividly on the novelistic stage, are seen from the outside, and reveal themselves only in speech. His novels are manic factories of plot: foundlings, lost heirs, faked letters, complex family inheritances.... Thus the rapid, farce-like, overlit simplicity of the happenings in Fielding—people getting into the wrong beds, hurling chamberpots of piss at each other, attacking the wrong people with cudgels and nearly beating them to death. No one is actually in danger of being beaten to death. It is a safe world, because a simple one. Controlling all this crazy busyness is an affable, attractive narrator...
If Fielding is (in Wood's words) "a great externalizer" then Richardson—whose masterpiece is the epistolary novel Clarissa (1747)—is the author associated with psychological depth and subjective inner worlds:
Richardson's minute epistolary method slows the novelistic examination of motive and desire to an agonizing lento, in which the individual perspective is everything. Plot expands and expires in Clarissa: there is a central, driving question—will Clarissa succumb?—and hardly a subplot of note in 1,300 pages. The labyrinthine belongs not to plot, but goes inward, into the human soul, and is inscribed in the advances and retreats, the feints and parries, the accommodations and resolutions, of the two central characters...
If Richardson was able to portray realistic characters, it was at least partially though his use of the epistolary form. Characters reveal themselves through their letters and speak with an immediacy and depth often not possible with even an omniscient narrator. In her recent book Inventing Human Rights, historian Lynn Hunt credits epistolary novels with developing a sense of empathy among their readers, leading to the necessary conditions for the conception of universal human rights. (See my blog entry about the book.)
Richardson's first major novel was Pamela (1740), about a maid who resists the sexual advances of her boss until her virtue is rewarded when he proposes legitimate marraige. Fielding's first major novel was a parody of Pamela called Shamela (1741), which exposed the character as a slut.
The difference between Fielding and Richardson that James Wood describes can be further simplified as a distinction betwee narratives that are "plot driven" and those that "character driven." Thackeray (Barry Lyndon, Vanity Fair) is obviously a descendent of Fielding, and so is Dickens to a large extent. The gothic novel of the 18th century and the sensation novel of the 19th century are certainly plot driven rather than character driven. When a major character surprisingly announces that she is "a mad woman" as happens in Mary Elizabeth Braddon's Lady Audley's Secret, you know you're in a world in which characters conform to plot twists rather than the other way around.
From the character-centric Richardson branch of the tree comes Jane Austen, Anthony Trollope, George Eliot, Henry James, as well as most of what's chosen for Oprah's Book Club.
The distinction is evident in popular film as well: There are "movies for guys who like movies" such as plot-driven action films, versus the character-driven "chick flicks."
Samuel Richardson's Clarissa—the novel I'm going to start reading in two days and finish six days after that—is the mother of all chick flicks.