The turning point...

Reading all the books in a series in order of publication, including the supposedly lesser early ones ("Why would you want to read those?"), does pay dividends every so often.

"The Doomsters" (1958), according to Ross Macdonald himself, and his biographer, is the book in which family traumas first led the novelist to turn inward and enrich the psychology of his Lew Archer detective series -- although it's the book immediately following, the eighth, "The Galton Case," that's usually indentified as the beginning of his most characteristic, great period.

So as I began reading it just this morning, I was in a position to know, with appropriate tingly/scalpy sensations, that this passage in Chapter 24 of "The Doomsters" was the first statement in any of his novels of one of Ross Macdonald's key themes. Archer is discussing his client, the troubled youngest son of one of the leading families of "Purissima" (aka. Ventura?), CA, with an administrator of the mental hospital from which the client has escaped:

"The type of family a sick man marries into" (Archer says) "can be very significant. A person who feels socially inadequate, as sick people do, will often lower himself in the social scale, deliberatly declass himself."

"Don't jump to conclusions too fast. You should take a look at his own family."

"Carl's told me a great deal about them. You know, when a person breaks down, he doesn't do it all by himself. It's something that happens to whole families. The terrible thing is when one member cracks up, the rest so often make a scapegoat out of him. They think they can solve their own problems by rejecting the sick one -- locking him up and forgetting him."

In a nutshell.

UPDATE:

P.D. James is mostly interested in Golden Age British detective fiction, but names Macdonald as her favorite writer of the American school:

Although Macdonald's complicated plots are not without violence, he is more a detached observer than a participant, resembling a secular Father Brown [!] in his empathy for human suffering. Less romantic than Chandler, his style has the vigor and imaginative richness of a man confident in his mastery of epithets and, particularly in his later novels, he attains a standard which places him first among those novelists who raised the genre from its roots in pulp fiction to serious literature.

For full effect, read aloud with fake accent.