I am not a native English speaker; I am Italian. I am always puzzled when I hear the expression "quid pro quo" intended as "you scratch my back I scratch yours". In Italy we mean it as "misunderstanding" (from the literal translation "this for that", with "for" meaning "in the place of" rather than "in exchange for").
Here is a dictionary entry Treccani La Cultura Italiana Online which translates to:
qui pro quo (or quiproquò) […] from the lat. quid pro quo, title of a section that in some pharmaceutical compilations of the late Middle Ages included the medicines that could be given in place of others; the modern meaning is taken from French. – Misunderstanding, exchange of people or data or news due to not having understood correctly, to have taken one thing for another.
What are your thoughts? To be more specific, I am asking what your thoughts are on the possible reasons for this discrepancy, and is it possible that it had both meanings in Latin as well?
Also, just to help further clarify: I am not curious about the meaning of the expression in modern Italian, but the meaning in modern English.
Best Answer
A look at two recent editions of popular U.S. dictionaries indicates that they do not explicitly recognize "scratch my back and I'll scratch yours" or "do me a favor and I'll do you a favor" as a distinct meaning of "quid pro quo."
Here is the entry for "quid pro quo" in Merriam-Webster's Eleventh Collegiate Dictionary (2003):
And here is the corresponding entry in The American Heritage Dictionary of the English Language, fifth edition (2010):
Nothing in these definitions points to a distinct implicit notion of kickbacks or pay-to-play or emoluments for favorable policy, although one could park such an idea in the broad contours of the expression, just as one could in the term reciprocity. But they do put the notion of "something of value for something else of value" squarely at the center of the term's meaning in English.
The most plausible explanation of why this meaning emerged victorious in English but not in Italian, I think, is that English usage derives primarily from the expression's meaning in one learned profession while Italian usage derives primarily from its meaning in another.
'Quid pro quo' in law
Use of quid pro quo to indicate an exchange of things of value goes back quite far in English law. Henry Black, A Dictionary of Law: Containing Definitions of the Terms and Phrases of American and English Jurisprudence, Ancient and Modern (1891) offers this brief discussion of the term:
And Giles Jacob, A New Law Dictionary Containing the Interpretation and Definition of Words and Terms Used in the Law, fifth edition (1744) has this:
Elsewhere in the same dictionary, Jacob defines consideration as "the material Cause or Quid pro quo, of any Contract, without which it will not be effectual or binding." And in explaining the nature of a binding contract, he says this:
It thus appears that the English legal system was so mistrustful of "something for nothing" that it made "something for something" the cornerstone of its contract law.
Stepping back farther still, Thomas Blount, Νομο-λεξικον: a Law-Dictionary (1691) has this entry for the expression:
And here is Blount again in Glossographia: or a Dictionary, Interpreting All Such Hard Words (1656):
So in 1656 Blount views the expression as a "hard word" and yet notes that it has leaked from the English Common Law into common speech, as well as emerging in the discourse of apothecaries. The "Kitch," or "Kitchin" mentioned in various law dictionary entries may be John Kitchin, an English judge who wrote the book Jurisdictions and who died in or before 1588.
Edward Coke, The First Part of the Institutes of the Lawes of England (1628):
W.G.'s 1651 translation from the Latin of John Cowell, The Institutes of the Lawes of England (1605) has this commentary (starting on page 184) in section 4 of a chapter titled "Of obligation by words":
A sixteenth-century instance of "quid pro quo" in a legal setting appears in William Lambarde, A Perambulation of Kent: Conteining the Description, Hystorie, and Customes of That Shyre (1576/1596):
But the oldest instance of "quid pro quo" in a legal context and in a book written predominantly in English is from Christopher St German, The Dialogve in English, betweene a Doctor of Diuinitie, and a Student in the Lawes of England (1528/1604):
St. German's book was originally published in 1528 but went through many subsequent editions. St German died in 1540.
'Quid pro quo' in medicine
The use of "quid pro quo" in medicine, as mentioned in the entry for the term in Blount's Glossographia (1656) noted above, is also quite old. From a 1535 translation of Desiderius Erasmus, A lytle treatise of the maner and forme of confession:
From "The Apothicaries rules" in William Bullein, Bulleins bulwarke of defence against all sicknesse, soarenesse, and woundes that doe dayly assaulte mankinde (1562/1579):
Another early and interesting instance of the term, used in the sense (as Blount points out) of substituting one medicinal preparation for another with supposedly similar properties, appears in John Securis, A Detection and Querimonie of the daily enormities and abuses comitted in physick, concernyng the thre parts therof: that is, the physitions part, the part of the surgeons, and the arte of poticaries (1566):
From John Gerard, The Herball or, Generall Historie of Plantes (1597):
From Francis Bacon, Of the Proficience and Advancement of learning, Divine and Humane (1605):
In this extract, Bacon uses receipts in its sense of "recipes."
'Quid pro quo' in politics and society
An early use of "quid pro quo" outside the fields of law and medicine appears in the course of a tedious religious polemic by N.D., An examen of the calendar or catalogue of protestan saincts, martyrs, and consellors, deuised by Ion Fox (1604):
The "quid pro quo" here is clearly the substitution for one claim or argument with a weaker or otherwise less suitable one, explicitly on the model of an apothecary substituting whatever happens to be in the shop for what the physician called for. The striking thing here is that the quid pro quo replacement is of one thing with another (in this case, another of inferior quality), not an exchange of things of theoretically equal value (as in the legal sense). It is thus a usage in the tradition that seems to have won out in Italian but ultimately died out in English.
Also interesting—as an early example of the potentially unsavory connotations of "quid pro quo" in the "value for value" sense—is this example from a 1639 translation by T.C. of Jean-Puget La Serre, The Mirrour Which Flatters Not:
The preceding example is the earliest one I've found that use "quid pro quo" to describe a situation that specifically involves dishonest behavior.
And here is an example of the phrase in a political context, from James Howell, Dendrologia: Dodona's grove; or, The vocall forrest (1640):
Assessment and conclusions
The phrase "quid pro quo" has appeared in texts written otherwise mostly in English for at least 490 years. The earliest example I found was from 1528, but I would not be at all surprised if even older examples exist.
The earliest examples of "quid pro quo" in English come arise in two distinct contexts: law (no later than 1528) and medicine (no later than 1535). And critically, the sense of the phrase "something for something" differs in the two fields.
In English common law, the sense of "quid pro quo" from its earliest days has amounted to "value for value"—that is "something for something" in contradistinction to "something for nothing." This conception of "quid pro quo" thus became a foundational requirement for a legally binding contract, a way of distinguishing an exchange from a gift or a theft.
In medicine, on the contrary, the sense of "quid pro quo" was "a makeshift substitute for something originally specified." The earliest published example of this usage in English is a translation of a treatise by Erasmus, who writes in 1535 that "quid pro quo" is a proverb among apothecaries in the Netherlands (and perhaps throughout Europe) to justify selling one drug or treatment in place of another. That learned observers viewed this practice with extreme suspicion is evident from Erasmus's description of its practical dangers and by the inclusion in William Bullein's "Apothicaries rules" in 1562 of a rule that the apothecary explicitly advise the buyer anytime the medicine being supplied was quid pro quo.
It is easy to see how these contrasting traditions of use for the same phrase might yield secondary meanings that are quite unlike each other. The legal "value for value" sense of "quid pro quo" invites subsequent use in the sense of "scratch my back and I'll scratch yours" or (more invidiously) "give me an unfair advantage on some project of importance to me, and I'll make sure that you are richly rewarded." The medical "best substitute available" sense, meanwhile, might predictably devolve into "whatever substitute I choose"; and if (as seems likely) the substitute is inferior to the originally prescribed item at treating the condition for which it was prescribed, it is easy to see how the inferior thing might be associated with misunderstanding or error.
In this regard, a snapshot of French usage of "quid pro quo" in 1611 seems quite revealing. Randle Cotgrave, A Dictionarie of the French and English Tongues (1611) provides three definitions for the phrase as used in contemporaneous French:
French in 1611 still had the baseline "one for another" meaning in play—but the tenor of the expression is undoubtedly colored by the other two meanings: a mistake and a gross error. I conjecture that these negative senses of "quid pro quo" arose from the apothecaries' proverb, because the consequences of that proverb lend themselves to deception and error. Just as significantly, French had no countervailing sense of "quid pro quo" as an exchange of things of presumed equal value voluntarily agreed upon by the contracting parties.
To my mind, the likeliest explanation for the divergence between Italian "quid pro quo" as misunderstanding and English "quid pro quo" as mutually advantageous arrangement is that Italian, like French, embraced the term through its medical/apothecary tradition whereas English ultimately abandoned that tradition of use in favor of the English common law sense of the term.