Why did post-structuralists turn away from structuralism? Did it become too mainstream? Nope, there were some big flaws and gaps in its explanation of how signs make meaning.
One problem was that signs don't produce one fixed meaning. Zach's beard evokes not only "hipster" but "gay bear", "hobo", "Hagrid" ... and so on.
One of the leading post-structuralists, Jacques Derrida, described meaning as being constantly "deferred". Signifiers don't point to an objective meaning – they just refer to other signs, which in turn point to yet other signs.
Derrida also criticised the tendency of structuralists to think in binary oppositions, like beard/clean-shaven. He urged us to "deconstruct" these pairs, which he called "violent hierarchies", by upturning them and showing the interplay between them.
Meanwhile, Michel Foucault showed how meanings change over time, creating power relationships and moulding our identities. How was the bearded hipster invented? Who benefits from its invention? How does hipsterism shape how we think and act?
Another post-structuralist, Jean Baudrillard, said that signs like hipster beards don't actually refer to real things any more. In our high-tech world, signs construct their own reality made up entirely of other signs, which he called "hyperreality".
Judith Butler used post-structuralist ideas to think about gender, arguing that – like signs – gender doesn't have a fixed essence. Rather, she famously said, gender is performed.
Similarly, queer theorists used post-structuralism to reject the idea of being either gay or straight. Rather, they invite us to embrace sexual identity in all its glittery diversity.
More recently, the field of animal studies is deconstructing the split between humans and animals – a "violent hierarchy" in which humans are dominant.
Post-structuralism – like the bearded hipster – has plenty of haters. And to be fair, it does have an annoying habit of being intentionally obscure. But it's had an undeniable impact on some important social and political issues.
Some say it's a fad whose time has passed. Others believe its insights will stick around for a long time to come, like a trusty old penny-farthing or a collection of early 80s Italo-disco on vinyl. What do you think?