Things are falling into place for the charming man-child at the center of “Some Girl(s),” Neil LaBute’s latest dissection of moral cowardice. The man has just published a chronicle of past romances in the New Yorker, and he’s about to get married. Then why is Guy (he has no name but is listed in the program as a “Guy,” so let’s go with that) jetting around the country in search of his ex-girlfriends?

This tousled-haired bounder will be familiar to those who know Mr. LaBute primarily from his earlier, unsparing chronicles of the evil that men and women (mostly men) do. But just as Mr. LaBute graduated from merely listing these wrongs to exploring the contradictory motivations behind them in layered works like “The Distance From Here” and “Fat Pig,” Guy is seemingly eager to get to the bottom of his caddish past.

“Some Girl(s),” in other words, features a fellow straight out of an old LaBute play trying to belong in one of the newer models. The degree to which he doesn’t succeed is what makes this thoughtful but static new work, directed probingly by Jo Bonney, a frustratingly in-between effort.

The entire play takes place in a series of anonymously swanky hotel rooms – Neil Patel’s witty set delineates them largely through their hideous artwork – where Guy (Eric McCormack of “Will and Grace” fame) has arranged a series of meetings. For reasons that only gradually become clear, he has embarked on a sort of premarital Stations of the Cross-Examination, pumping one ex after the next for an odd blend of admiration and absolution as he dredges up “a kind of faint memory of hurting.”

Among these former conquests – Guy makes it clear that this is hardly a comprehensive list – are his high school sweetheart (Brooke Smith, the only performer here without extensive sitcom experience), a sexually voracious artist (Judy Reyes), a buttoned-down married woman with a wild streak (Fran Drescher), and a dirty blonde from California (Maura Tierney). Not so coincidentally, this amounts to a laundry list of typical male Fantasyland: The blonde even has an identical twin.

One of them refers to Guy’s sojourn as a “rake’s progress,” and while the first part of that statement is indisputable, the word “progress” implies that our protagonist learns or actually progresses as a result of his travels. Not this rake: Guy wants to be forgiven without actually apologizing for much. Unsurprisingly, this plan doesn’t go very well.

It’s unclear what he’s really after for much of “Some Girl(s),” and it’s equally murky what Mr. LaBute wants from Guy. The title’s optional plural after “Girl” would suggest that the women are interchangeable, but it’s Guy who remains superficial. No matter where or how far back he goes, there he is – a clean-cut, faux earnest guy with a talent for saying and doing the wrong things. Lindsay, the older professor (a surprisingly subdued Ms. Drescher), dismisses him as “the kind of person who leaves a bunch of hurt in your boyish wake,” and it’s hard not to agree with her.

Even with a fraction of the stage time (the play is divided almost exactly into four quarters), each of the women registers as a more complicated, rounded character than Guy. This may be intentional – only very late in the play does Mr. LaBute suggest a motive to Guy’s travels beyond just garden-variety neediness. This comes via one of his late-stage plot twists that threaten to descend into gimmickry. (Without giving too much away, he employed an almost identical twist to more devastating effect in an earlier play.)

But this vagueness also takes away many of the tools that his leading man might otherwise have used. The same sorts of statements offend each one of Guy’s four ex-girlfriends, and yet he’s somehow surprised each time? How is Mr. McCormack supposed to play that? As it happens, he does all right with Guy’s limited emotional range, although Ms. Bonney allows him to fall back on the occasional bit of sitcom physicality.

With the exception of Guy’s evisceration at the hands of Lindsay – which is gratifying in theory but dramatically forced – the scenes work well as individual confrontations. Ms. Smith comes off best as the most fragile ex, and Ms. Tierney shows a welcome nasty side, but all four actresses shrewdly embrace the flashes of awkwardness and long-suppressed resentments.

As Stephen Sondheim and George Furth demonstrated in “Company,” building a play around a dissatisfied thirty-something bachelor is difficult but not impossible. Their creation, Bobby, offered this memorable summation of a relationship: “Parallel lines / Who meet.” Guy has upped the mathematical complexity in “Some Girl(s),” titling his New Yorker article “The Calculus of Desire.” But Mr. LaBute, perhaps by design, has invented a protagonist who has trouble counting beyond the number one. After the complex dynamics that have invigorated his recent works, it’s hard not to view this as a step backward.

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