Anti-anthropocentrism is the idea that humans are insignificant. It is the opposing view of Anthropocentrism. It has risen to a universal principle in recent decades. It is fashionable to relegate humanity to the dustbin of insignificance based on the religion of Bayesianism. It goes by the so-called Mediocrity Principle — that earth, our solar system, and ultimately we as a species are all (probably) cosmically insignificant. It is a philosophical claim that holds more sway in the scientific community than in the general public.
It reduces us to objects drawn from a metaphorical cosmic urn. While intended to dispel hubris in our quest for objective knowledge, it achieves the perverse outcome of singling us out as ordinary. Its fallacy lies in the core arguments supporting the claim that gets dismissed as unworthy of explanation. Those are (a) our ability to reason and (b) its byproduct, the exponential knowledge growth. Before we critique anti-anthropocentrism, it helps to bolster its central theme.
The Enlightenment movement got spurred by a severe allergic reaction to authority. Entrenched doctrines defending a constellation of bad ideas hindered human progress. The scientific inquiry was a slap in the face of the Geocentrism they espoused. As society realized its fears were unfounded, they had to crumble, dislodging us from our cozy anthropocentric perch.
Physical phenomena are impersonal, devoid of intentions of supernatural entities or immaterial spirits. And parsimoniously explicable without appealing to divine benevolence or wrath. Getting unshackled from the grip of bad memes passed down from antiquity must have been liberating. When viewed through this lens, anti-anthropocentrism seems reasonable, even necessary.
Consider a large urn filled with balls of different colors, not all equally numerous. A ball drawn at random, a stand-in for humanity or our planet or solar system, is more likely to be of the most common color — hence Mediocrity Principle. By invoking Bayesian calculus, it suggests we floor our expectations, justifying the claim that we are remarkably unremarkable.