LIKE most children of the Reagan era, I grew up with a steady diet of media warnings about the perils of religious cults — the gurus who lurked in wait for the unwary and confused, offering absolute certainty with the aftertaste of poisoned Kool-Aid. From the 1970s through the 1990s, from Jonestown to Heaven’s Gate, frightening fringe groups and their charismatic leaders seemed like an essential element of the American religious landscape.

Yet we don’t hear nearly as much about them anymore, and it isn’t just that the media have moved on. Some strange experiments have aged into respectability, some sinister ones still flourish, but over all the cult phenomenon feels increasingly antique, like lava lamps and bell bottoms. Spiritual gurus still flourish in our era, of course, but they are generally comforting, vapid, safe — a Joel Osteen rather than a Jim Jones, a Deepak Chopra rather than a David Koresh.

Twice in the last few months I’ve encountered writers taking note of this shift, and both have made a similar (and provocative) point: The decline of cults, while good news for anxious parents of potential devotees, might actually be a worrying sign for Western culture, an indicator not only of religious stagnation but of declining creativity writ large.