Molly was a capricious woman. Her moods were unpredictable, her anger petty and vicious.
-- Rand Roberts and James Olson, John Wayne: American
He knew that the Board would rule against him; he knew that the key to the dark, capricious mystery of the Board's contradictory decisions was the secret power of pull.
-- Ayn Rand, Atlas Shrugged
Mathematics is logical; people are erratic, capricious, and barely comprehensible.
-- Bruce Schneier, Secrets and Lies: Digital Security in a Networked World
Capricious comes, via French, from Italian capriccio, a shivering, a shudder, finally (influenced by Italian capra, goat) a whim, from capo, head (from Latin caput) + riccio, hedgehog (from Latin ericius). The basic idea is that of a head with hair standing on end, like the spines of a hedgehog.