isle

Isle entered English in the late thirteenth century from Old French, which had inherited it from Latin insula, the ordinary word for an island.‌​‌​‍​‍​‌​‌​‍​‍​‌​‌​‍​‍​‍​‍​‍​‌​‍​‍​‍​‌​‍​‌​‍​‌​‌​‌​‍​‍​‌​‍​‌​‍ The word belongs to a sprawling Romance family — French île, Italian isola, Spanish isla, Portuguese ilha, Romanian insulă, Catalan illa — and through its Latin parent to a thick English undergrowth of insular, insulate, isolate, peninsula, and even insulin. Behind all of them sits the same four-syllable Latin noun and a spelling accident four centuries old. The ultimate origin of insula itself is unsettled; no clean Indo-European root has ever been agreed. Proposals range from a compound meaning roughly in-the-sea to a borrowing from a pre-Roman Mediterranean substrate language, the same shadowy source suspected behind Latin rosa and cupressus. Etymologists have been disputing it since at least Varro in the first century BCE, and disputed it remains.

The most interesting thing about isle, however, is the s. By the eleventh century, French speakers had stopped pronouncing the s between vowels, so Old French ile sounded roughly like modern île. English borrowed the word in that silent-s era: the earliest attestations, around 1290, are spelled ile, yle, or ylle, with no s anywhere. But Middle English scribes, trained in medieval Latin, could see the parent word insula standing behind the spoken form, and in the fifteenth and sixteenth centuries they quietly restored the s on the page — a written tribute to a pronunciation that was already two hundred years gone. French eventually gave up on the silent letter and marked its absence with a circumflex: île. English kept the older, more cluttered spelling, and has kept it ever since. Caxton prints isle in 1481; Shakespeare writes it throughout the First Folio (1623); Johnson enters it in his Dictionary (1755) with the cross-reference to island already firmly in place.

The same Latinising impulse then wandered over to a completely unrelated word. Island is Germanic, not Latin — from Old English īegland, a compound of īeg (watery place, from Proto-Germanic *awjō) and land. It was spelled igland, yland, or iland for centuries, with no s anywhere. Then the same sixteenth-century scholarly scribes, assuming any word meaning island must somehow be related to insula, inserted an s into island as well. That s has no historical justification. It has been silent ever since. Two silent letters, one fashion, both installed by scribes who preferred Latin etymology to English history.

The Latin root has been unusually productive. Insular (island-like, and by extension narrow-minded) is attested from the 1610s. Insulate (to surround, to make island-like) appears in Browne's Pseudodoxia Epidemica (1646). Peninsula is almost-island, Latin paene (almost) plus insula, first recorded in English in 1538 in descriptions of European geography. Insulin takes its name from the islets of Langerhans, the tiny island-like clusters of cells in the pancreas first described by Paul Langerhans in 1869; the hormone was named in 1916 and isolated at Toronto in 1921. Isolate comes via Italian isolato, one set apart as if on an island — a seventeenth-century architectural term for a building that stood alone, only later extended to people and experimental subjects.

The Romance cognates are worth a closer look. Latin insula passed through Vulgar Latin into each daughter language along a regular sound path. Initial i- is preserved everywhere. The -ns- cluster simplified to -s- or -z- (Italian isola, Spanish isla), except in learned Romanian borrowings (insulă) which restored the Latin form from the written tradition. The final -a is retained in the feminine Romance languages and lost in French, where word-final vowels weakened to schwa and eventually dropped (île). The s that French later wrote as a circumflex is the same s that English was simultaneously restoring as a letter — the two traditions reached the opposite solution to the same problem. Catalan illa went further still, palatalising the -s- into a double l. All of them point to the same Latin noun and all of them, except Romanian, lost the s in speech before their orthographies caught up.

In modern English, isle has narrowed into a literary and ceremonial register. It survives mostly in place names — the Isle of Wight, the Isle of Man, the British Isles, the Isle of Skye, the Emerald Isle — and in poetry, where it carries a quiet romance that the workaday island cannot match. Shakespeare sets The Tempest (1611) on an unnamed isle and has John of Gaunt call England "this sceptred isle" in Richard II (1597). Milton opens Paradise Lost with the garden on its isle. Tennyson sends Arthur to the Isle of Avalon in Idylls of the King. Keats writes of "the isle of Wight" in a letter. The distinction between isle and island is one of tone rather than meaning: isle belongs to legend and cartography, island to the atlas. A fisherman lives on an island; a shipwrecked hero washes up on an isle. One is geography; the other is myth with a coastline.