海角大神

One Latin phrase has come up over and over in the past year: quid pro quo. It defines the central question of President Donald Trump鈥檚 dealings with Ukraine 鈥� did he make military funding contingent on an investigation into Joe Biden and his family? This is a language column, so we won鈥檛 go into the politics. Instead let鈥檚 talk about the many words and phrases, like quid pro quo, that English has acquired from the multifarious Latin pronouns quis and qui.

These pronouns are often indistinguishable in Latin, and mean more or less the same thing: 鈥渨ho,鈥� 鈥渨hat,鈥� 鈥渨hich,鈥� and 鈥渟omeone, something.鈥� Quis is clearly visible in the Roman satirist Juvenal鈥檚 famous question, 鈥�Quis custodiet ipsos custodes?鈥� or 鈥淲ho will guard the guards themselves?鈥� In English, this phrase is often used to highlight the dangers of corruption among the powerful. They watch us; who watches them?

But Latin nouns and pronouns decline, changing shape depending on the role they play in the sentence. Quid pro quo itself is just two different forms of quis, its neuter nominative form quid plus its ablative form quo. The phrase means 鈥渟omething for something.鈥� 聽

Quomodo is 鈥渢he manner, the means,鈥� as in these lines from Henry Fielding鈥檚 classic 鈥淭om Jones鈥� (1749): 鈥淣ortherton was desirous of departing ... and nothing remained for him but to contrive the Quomodo.鈥澛�

The feminine form of quo is qua, which gives us the sine qua non: the 鈥渨ithout which, not,鈥� or better translated, the 鈥渆ssential, indispensable.鈥�

In the dative case, used to indicate the recipient of a thing or action, quis becomes cui. 鈥�Cui bono?鈥� 鈥� the question asked in hundreds of courtrooms and detective novels 鈥� means 鈥渢o whom for a benefit?鈥� or, more elegantly, 鈥渨ho profits?鈥�

The genitive plural contributed quorum (鈥渙f whom鈥�), which means 鈥渢he number ... of officers or members of a body that when duly assembled is legally competent to transact business.鈥澛�

In English, quid is related both to the deepest mysteries of being and to the glibbest trivialities. From the 17th century, quid has meant 鈥渢hat which a thing is,鈥� its essence. When a character in a 19th-century play says, 鈥淢y age has seen ... the quid of things,鈥� he is talking about the wisdom he has gained as he has grown older. But quid also produced quiddity, which often means 鈥渁 trifling point鈥�; quibble, to make frivolous objections; and quip, a cutting or witty remark. 聽

When mathematicians finish a proof, they can employ another qui relative, quod erat demonstrandum 鈥� 鈥�(that) which was to be demonstrated.鈥� This indicates they believe they have proved the problem satisfactorily. So, Q.E.D., or as my high school geometry teacher translated it, 鈥渜uit, enough done.鈥�