In a riposte to Jessa Crispin's recent complaint that a besieged literary culture has been too quick to "close ranks," leading some review editors to prefer only positive reviews, Bethanne Patrick wants to remind us that "Positive reviews, well-written and carefully thought out, certainly are part of criticism." This is, of course, correct, and Patrick does not suggest that, conversely, negative reviews are somehow not part of criticism. Indeed, she confesses to engaging in excessive "boosterism" in her own efforts as editor and book reviewer, ultimately declining the role of "book cheerleader," an inclination to which does indeed characterize a great deal of what is called "literary journalism," and the performance of which too often substitutes for actual literary criticism in both print and online publications.
A positive review does not have to be merely an instance of book cheerleading, however. I would argue that a genuinely "carefully thought out" positive review can be harder to do well than a negative review, since writing a review of a book one finds disappointing, or even actively dislikes, focuses a critic's attention in a way that can be more difficult when trying to account for what one likes in a good book. Those qualities that contribute to a work's failure of interest are likely to make themselves felt distinctly over the duration of the reading experience, leaving the critic with a fairly acute perception of what went wrong in the work. A successful book, a book that consistently engages attention and fulfills its aesthetic ambitions, can challenge the critic to go beyond generic praise and empty accolades, to summon a critical language that doesn't simply repeat, in different variations, "This is a good book."
The most common type of positive review, to be found across the spectrum of available critical opinion, from personal blogs to front page reviews in the New York Times Book Review, employs the rhetoric of extravagant, hyperbolic acclamation, usually leaning heavily on a few all-purpose terms of fulsome praise: "astonishing;" "incandescent;" "rapturous;" "stunning." Most of these terms are more or less interchangeable, and are used so frequently in so many different contexts that they have essentially become meaningless. Unfortunately, most reviews that use such language rely on it as their primary mode of appraisal, at most adding further plot summary, as if reminding us of the story or summing up characters will suffice as illustration of the pertinence of these hopelessly nebulous adjectives as applied to the book at hand.
This sort of review implicitly accepts the conception of reviews as consumer guides, advice to the reader about whether a book is worth his/her time and money. It affirms the evaluative function of criticism (as, of course, does the negative review as well) at the expense of the descriptive function, at least if "description" means more than highlighting and recapitulating narrative content. If newspaper book reviews--to the extent they survive--are not likely to ever abandon this model, reviews in cultural magazines, literary journals, and online generally have no particular reason to embrace it, and thus we could expect reviews from these sources to more often incorporate the descriptive function of criticism, to more fully convey to the reader an impression of the critic's own experience of reading. In this context, a positive review doesn't just commend a book to its potential readers or offer praise and approval to the author (although it could do both of these things), but tries to make manifest the "imaginative qualities" the critic has fathomed in that actual thing--the literary work--readers now and in the future might more fruitfully appreciate.
This means the most valuable skill the critic can bring to the consideration of books, specifically poetry or fiction, is the ability to pay close but also receptive attention--receptive especially to goals and strategies that might seem unfamiliar or unorthodox. Simply calling such a strategy "incandescent" without explaining how it works (or why it prompts a metaphor that invokes giving off light rather than, say, an auditory metaphor) doesn't really help us assimilate its intention or effect. Similarly, a negative review that dismisses an unfamiliar strategy simply because it is unfamiliar does no service either to the book in question or to the efficacy of literary criticism. This sort of reflexively dismissive negative review is arguably even more useless as criticism than the cheerleading panegyric. An enthusiastic but opaque positive review can be correct in its judgment if inadequate in its justification; an uncomprehending negative review provides no reason to take it seriously to begin with.
A well-executed positive review performs an entirely legitimate function of literary criticism. It offers a sort of baseline affirmative analysis that other reviews or critical essays might need to challenge, although not necessarily in an explicit way. To the extent that an intelligent contemporaneous review of a novel that continues to attract readers and critical attention into the future forms a part of the lasting critical discourse about that novel, criticism later readers might consider, a "carefully thought out" positive review would play its part in the study, formal or informal, of the work. Less tangibly, a convincing positive review partly determines the tenor of the conversation about a new book, in some cases no doubt directly affecting the consensus of opinion about it. Negative reviews do this as well, of course, but this is most likely with a prominent "takedown" kind of review. Since positive reviews of fiction usually outnumber negative reviews, a good one needs to be especially good to stand out.