 Readers of the Observations would have been familiar with the words “decompound” and “decomposite”—both from the late Latin decompositus, a rendering of the Greek parasynthetos—in which the “de-” prefix signifies “repeatedly” or “further.” They would also know the word “complex,” from Locke’s Essay concerning Human Understanding: “Ideas thus made up of several simple ones put together, I call Complex; such as are Beauty, Gratitude, a Man, an Army, the Universe” (Locke [1690] 1975, 2.12.1).