If any one writer is to blame for the decline of the comic novel in England it is Kingsley Amis. Before the war, in the hands of writers like Gerhardie, Waugh and early Compton-Burnett, it was not inconceivable that the comic novel could be intellectually interesting, or be written with a bit of linguistic invention. What followed from Amis's novels were dismal comedies by Tom Sharpe or David Lodge about buying contraceptives.

Amis shut off large parts of his intelligence in favour of facetiousness, and the results have dated appallingly. Jake's Thing is a comedy about the folly of admitting women to Oxbridge men's colleges, of all the utterly dead subjects. Take a Girl Like You is a comedy about predatory men and virginal women in the permissive society, and took about a micro-second to descend to the intellectual level of the writers of situation comedies. You Can't Do Both is not exactly a funny book—at least, like A. S. Byatt's Frederica Potter reading Lucky Jim, I didn't notice any jokes—but its whimsical, jocular tone makes all the gestures.

If Amis's books are put next to the works of his contemporaries, the immediately apparent thing is that they are simply not funny any more. It isn't that they have no ideas, it might actually be said that the fault with a good deal of Amis's output is that it has too many ideas and not enough thought. I Want it Now seems as distant and exotic, and about as rib-tickling, as The Tale Of Genji. Michael Frayn's novels, on the other hand, or Auberon Waugh's don't give the impression that their authors stopped thinking seriously as they began to write; as a result, books like Towards the End Of The Morning or Waugh's Consider the Lilies are not only still dazzlingly intelligent, but dazzlingly funny. But it was Amis who got the imitators, perhaps because his sort of comedy was considerably easier to do.

Thirty years ago, Frayn was ridiculing Amis in The Tin Men with devastating effect. “‘Oh, God,’ groaned Patrick. ‘Back to square one. Do you think there's something wrong with a healthy dollop of good old British snogging between blokes and blokesses?’” But You Can't Do Both is still stuck in the same saloon-bar facetiousness, the same fusty embarrassment. “It's sort of funny in a way that you should be telling me you've got old Nancy into the pudding club at last … you see, I've recently put Elizabeth into the very same club.”

It's not good enough to say that these are Amis's characters talking, and not Amis; what his characters say corresponds too well with his own unwillingness to examine his characters' emotional state. Amis is not an unembarrassed chronicler of embarrassment; he takes his own shame to be not just universal, but exemplary.

You Can't Do Both is an unusually bad book, and bad in very ordinary ways: the ways which generally lead publishers to reject manuscripts. For an author of Amis's experience, it is often astoundingly inept: the chinking transitions, for instance. “Chapter Two: Robin Davies, second-year undergraduate at Oxford University, laid aside his copy of Vanderdecken. … Practically every physical detail has a strangely inert air—“Like Robin, both wore the navy-blue school cap and tie with a white shirt and black shoes; unlike him in his black jacket and grey trousers they were in grey flannel suits, this being the summer term.” Such details are either there as period colour or for no good reason: the objects a character surrounds himself with never tell you much about the character.

It is billed as an autobiographical novel, and, as so often with autobiographical fiction, an air of improbability hangs over the whole thing. Arguments are on the whole settled too decisively, and generally settled by the hero, putting his opponents down with a fluency which generally occurs in real life in the back of taxis on the way home.

Many of the cast are sketched too loosely, as if Amis feels that we ought to know their originals as well as he does from real life—in fact, we know them best from other fictions. The hero's father, for instance, is a kind of heavy Victorian father without the religion who undergoes a death-bed conversion to niceness. The hero's mother is a downtrodden doormat who has inner strength. After her husband's death she, too, starts to get the best of arguments.

You Can't Do Both is a worthy successor in every respect to I Like It Here, Take a Girl Like You, I Want it Now, and It Just Goes To Show—oh, all right, I made that last one up. It's being hailed on all sides as Amis's best novel since The Old Devils, but you might as well call it his best novel since Jake's Thing without paying it much more of a compliment. It is the work, in the end, of somebody with confidence in what he thinks he can do, and who is going to do it once more.