plateau

Plateau comes from Old French platel, a diminutive of plat ('flat, plate'), which derives from Medieval Latin plattus, borrowed from Greek πλατύς (platýs, 'flat, broad, wide'). The Greek root is the same one that gives us 'platitude' (a flat, obvious remark) and that names the city of Plato (whose name means 'broad-shouldered'). The word plat described flatness as a fundamental quality, and the French developed it through their culinary vocabulary — a plateau was first a flat serving dish or tray before it became a geographical term. The naming of high, flat landforms as plateaux was a natural extension: the land looked like a tray, elevated and flat, and the kitchen word scaled to continental dimensions.

The plateau as a geographical concept was formalized in French and English scientific writing of the eighteenth and nineteenth centuries, as explorers and cartographers encountered and needed to describe the high flat tablelands of the American West, the East African Rift highlands, the Tibetan massif, and the Anatolian plain. The Tibetan Plateau — covering roughly 2.5 million square kilometers at an average elevation of 4,500 meters — is the largest and highest plateau on Earth, called the 'Roof of the World.' It was given the French-derived English name in European geographical writing, though Tibetans had their own vocabulary for their landscape: Bö (Tibet) simply meaning the territory, its extraordinary altitude unemphasized because for those who lived there, altitude was merely the condition of existence.

The word acquired a figurative life in English and French by the late nineteenth century, naming any period of stable equilibrium after a period of change. A learning plateau is the phase after initial rapid acquisition when progress seems to stall before resuming. An economic plateau is a period of stable output between growth cycles. A fever plateau is the sustained high temperature after the initial spike. In every figurative use, the geographical metaphor is precise: a plateau is not the peak but the flat after the climb, not the descent but the level ground that follows ascent. Progress has a topography, and the plateau is its flat country.

The French word itself has been borrowed back into geological French from English as a semi-technical term, and it circulates internationally without translation in scientific writing. The plateau, as both landform and metaphor, has traveled further from its origin as a dinner plate than almost any kitchen word in European languages. A flat piece of crockery holding roasted meats became, through the expansion of European geographical knowledge and the subsequent import of that vocabulary into science and psychology, the name for the world's most enduring elevated landmasses and the most frustrating phases of learning. The plate was always there; it just grew larger and rose higher.