Anaclasis (poetry)

Anaclasis /əˈnækləsɪs/^[1][2] (from the Greek ἀνάκλασις "bending back, reflection") is a feature of poetic metre, in which a long and a short syllable (or long and anceps syllable) exchange places in a metrical pattern.

Ancient metricians used the term principally of the Greek galliambic rhythm | u u – u | – u – – |, which they believed was derived from a regular ionic dimeter | u u – – | u u – – | by a reversal of syllables 4 and 5, creating metra of unequal length | u u – u | and | – – u – |.

Although the original meaning of the term anaclasis referred to situations when the substitution of u – for – u occurred across the boundary between two metra, in modern times scholars have extended the term to any situation where the sequence x – (anceps + long) responds to – x (long + anceps) in a parallel part of a verse or poem.^[3] Thus for example, Martin West applies the term to metres of the aeolic type, in which sometimes | – x – u | or | u – u – | are treated as interchangeable with | – u u – |.^[4]

A similar phenomenon has also been observed in classical Persian poetry, for example in the metre of the ruba'i (quatrain), in which the iambic | u – u – | and choriambic | – u u – | rhythms can be used as alternatives in the same poem. Persian also exhibits a second form of anaclasis, in which the ionic dimeter | u u – – | u u – – | exists alongside | u – u – | u u – – |, with reversal of syllables 2 and 3.^[5] The metrician Paul Kiparsky has argued that anaclasis (or "syncopation") is a common feature of Greek, Sanskrit, and Persian metres and believes that is inherited from Indo-European poetry.^[6]

In English a feature similar to anaclasis can be found in inversion in the iambic pentameter, when stressed and unstressed elements are reversed, especially at the beginning of a line.

In optics, the word "anaclasis" refers to the bending of light as it passes from a less dense to a more dense medium. A ray of light entering a pool of water from an angle will be bent downwards.^[2]

Connected with anaclasis is the adjective anaclastic, but this is a relatively modern formation, first recorded, in an optical sense, in the 18th century.^[7]