The secret to the enduring allure of “Fight Club” may be that it is, as Mr. Norton put it, quoting Mr. Fincher, “a serious film made by deeply unserious people.” In other words, a film as willing to take on profound questions as it is to laugh at and contradict itself: what is “Fight Club” if not the most fashionable commercial imaginable for anti-materialism? A movie of big ideas and abundant ambiguities, it can be read and reread in many ways.It's something we inherited from the anti-anti-utopians. The impulse toward ha! ha! just serious.