One of the best ways to come up with an idea for a book, it seems, is to devise a new way of being specific. In recent years authors have written books about a specific color, a specific type of fish, or a specific condiment. These books work when they convincingly isolate a blind spot – how has salt changed the world? Sianne Ngai, an assistant professor of English at Stanford, has written an ambitious book about an entirely new class of feelings: “Ugly Feelings” (Harvard University Press, $29.95, 422 pages).

But Ms. Ngai’s book makes sense only insofar as her choice of seven feelings – envy, irritation, anxiety, paranoia, disgust, and, more intriguingly, “animatedness” and “stuplimity” – can be justified. How are these feelings any more “ugly” than deceit, hate, or even shame? If her book is “a bestiary of affects,” she writes, “it is one filled with rats and possums rather than lions, its categories of feeling generally being, well, weaker and nastier.” By “weaker,” Ms. Ngai means feelings that do not really have a distinct cause or effect but simply simmer, miserably.

Every age flatters itself that it produces its own unique emotions, but the emotions themselves are usually not themselves very flattering. In the 19th century, ennui and neurasthenia were the watchwords. Ms. Ngai feels that today “our emotions no longer link up as securely as they once did,” and are “less powerful than the classical political passions.” These are big assertions – there seems to have been a lot of classic political passion lately. But Ms. Ngai’s more specific speculation that conspiracy theories were “quietly claimed as a masculine prerogative in the last decades of the 20th century,” rings more true; think of the “X-Files’s” Mulder and Scully, in which the somewhat paranoid male member of the pair was always right.

More important than temporal distinctions is Ms. Ngai’s notion that these are feelings of “restricted agency,” in which the individual loses track of his own control and, in her terms, becomes confused about “feeling’s objective or subjective status.” In other words, the ugly feeling in question might be an honest response to some irksome stimulus, or it might just be an arbitrary function of a bad mood.

Confusion about where the feeling comes from makes things worse: Trying to figure out why one is so irritated can be irritating. Even Aristotle wrote that, “Those people we call irritable are those who are irritated by the wrong things, more severely and for longer than is right.”

The prevalence in our culture of recursiveness – the feedback loop – is one of Ms. Ngai’s most stimulating observations: It is what rock music, Andy Warhol, and Philip Glass have in common. The topic comes up first in Ms. Ngai’s chapter on tone, where she leans somewhat eccentrically on the work of psychologist Silvan Tomkins. It appears again in Ms. Ngai’s chapter of “Stuplimity.”

Except for the inescapably ridiculous sound of that neologism, Ms. Ngai makes a convincing case for a new kind of sublimity: a kind of awesomeness that is not “inspiriting,” per Kant, but that drags us downwards, towards stupidity. Gertrude Stein wrote that “There is a stupid being in every one,” and Ms. Ngai cites Stein’s interest in how “astonishment and fatigue” can work in tandem.”

The essence of “stuplimity” is a “temporary paralysis of mind” in which hyperactivity paradoxically deadens our thinking. Critics of the avant-garde have seldom been so comfortably frank about the “prominence of tedium as an aesthetic strategy” in avant-garde practices, and Ms. Ngai very convincingly likens it to the “highly energized, yet exhaustively durational electronic music known as techno.”

Less convincing is Ms. Ngai’s chapter on “animatedness.” She compares the stop-motion techniques of cartoon or Claymation to the racially marked “animatedness” of figures like Harriet Beecher Stowe’s Topsy or Warner Bros. Speedy Gonzales. It is true that animation is not only condescended to as a medium, but itself condescends to its characters. But the link between that condescension and racist stereotypes is weak. Ms. Ngai seems to pun on the phrase “being moved,” as in the “overemotional racial subject,” and later makes the fairly precious observation that “emotional qualities seem especially prone to sliding into corporeal qualities where the African-American subject is concerned.”

“Ugly Feelings” is a deeply scholarly book, and sometimes Ms. Ngai’s own thoughts barely surface amid her extensive examples, which are themselves sometimes “stuplifying.” The book’s worth lies in its ambition, even its overreach. This is no cultural-studies grab-bag; Ms. Ngai really is breaking new ground.