I agree that Sokal's point of view was uncharitable to the majority of post-structuralists, but I can attest to the fact there is a definite strain of radical relativism on today's campuses. It goes hand in hand with a reflexive questioning of authority, an attitude that views all authority as illegitimate, even when that authority is derived from legitimate learning and knowledge. And when that attitude confronts science, it becomes a rationalization to challenge or deny universal theories that have been proven repeatedly by experiment as somehow merely a 'local' knowledge framework, or 'culturally constructed' or 'patriarchal' and therefore something to be suspicious of. This opens the door to treating all scientific assertions as equivalent and suspect. And you can draw a straight line from that to the anti-intellectualism that dominates our social discourse today.

As to your question, in many ways calling Einstein's theory 'relativity' was a misnomer because it was actually a statement about the absolute laws of physical reality - laws that don't change with perspective or reference frame. For example, for special relativity, the absolute laws of electrodynamics require the speed of light to remain constant in every reference frame. And these laws entail that space and time must change with reference frame in order for the laws of physics to remain absolute. For these reasons, the relativity of physics bears little resemblance to moral relativism.

> you can draw a straight line from that to the anti-intellectualism that dominates our social discourse today

Really? Could you elaborate?

From my perspective, the two groups you connect seem more opposed than anything. The prevailing strains of anti-intellectualism despise what they perceive as ivory-tower academia, and the sorts of people who dabble in poststructuralism & the like tend to be the very model of the anti-intellectuals' villain. To, say, the average climate change denier, the social sciences aren't "real science", they're only good for jobs at Starbucks - and if critical theory's even on their radar, it's as an enemy, lumped in with the "cultural marxism" bogeyman.

But that's just the thing, I don't think post-structuralism and platonism are mutually exclusive, and neither would, say, deleuze. "Things are absolutely relative to their frame of reference." I would consider that formulation perfectly consistent with plenty of, say, morally relativist interpretations. And Kant's "Newtonian" lack of relativism is exactly the shortcoming his categorical imperative.

What are the key differences between Einsteinian relativity and ordinary Newtonian relativity that would invite you to make such an analogy?

You mean the difference between space as a medium in which things sit as opposed to space as constituted but the objects that populate it? I would say the perspectivism implied by the latter.

I'm not sure Einstein's theory says that, actually. The equations have solutions without any matter or electrical fields, yet where gravity twists itself into nontrivial shapes. It's more accurate to say that stuff can affect space and vice versa, not that space is defined by stuff.