Of all movements in art and design history, postmodernism is perhaps the most controversial. This era defies definition, but it is a perfect subject for an exhibition. Postmodernism was an unstable mix of the theatrical and theoretical. It was visually thrilling, a multifaceted style that ranged from the colorful to the ruinous, the ludicrous to the luxurious. What they all had in common was a drastic departure from modernism’s utopian visions, which had been based on clarity and simplicity. The modernists wanted to open a window onto a new world. Postmodernism, by contrast, was more like a broken mirror, a reflecting surface made of many fragments. Its key principles were complexity and contradiction. It was meant to resist authority, yet over the course of two decades, from about 1970 to 1990, it became enmeshed in the very circuits of money and influence that it had initially sought to dismantle. Postmodernism shattered established ideas about style. It brought a radical freedom to art and design, through gestures that were often funny, sometimes confrontational and occasionally absurd. Most of all, postmodernism brought a new self-awareness about style itself. Postmodernism: Style and Subversion 1970 to 1990 is on view until January 15 at the Victoria & Albert Museum in London.