the.com/essentialism

means The idea that things (and people) have a fixed, defining core nature that makes them what they are, independent of context or circumstance — used both as a philosophical position and, more casually, to describe focusing on only what truly matters.

from Built from 'essence,' which traces back to Latin 'essentia,' a word coined (the trail leads to Cicero or thereabouts) to translate Greek philosophical terms for 'being' — from 'esse,' to be. The '-ism' tacked on turns a quality into a doctrine. The philosophical sense (every category has a defining nature) is ancient, rooted in Plato and Aristotle's hunt for the fixed 'whatness' of things. The leaner, popular 'focus on what matters' sense is a modern rebranding, riding on the older word's gravity to make decluttering sound like philosophy.