Sign that reads, “no parking this side.” This fact that there is an exception forbidding parking on one side of the street indicates that parking on the other side of the street is permitted.
19 October 2022
The exception proves the rule is an odd phrase for present-day speakers of English. It seems illogical to demonstrate the truth of something by using evidence that contradicts it. But it is a translation of an old Latin maxim that states the presence of an exception to a law is evidence that the law exists. For instance, if you see a sign that says “no parking on Sundays,” you can be sure that parking is allowed the other six days of the week.
English use of the Latin maxim starts appearing in the seventeenth century. In a 1617 tract holding that the king had authority over bishops, theologian Samuel Collins wrote:
Haue you not heard, that indefinites are equiualent to vniuersalls, especially where one exception beeing made, it is plaine that all others are thereby cut off, according to the rule Exceptio figit regulam in non exceptis.
The Latin translates as: the exception establishes the rule in [cases] not excepted.
And in his 1623 De augmentis scientiarum, Francis Bacon gives this aphorism as number seventeen in a list of such maxims:
In legibus et statutis brevioris stili, extensio facienda est liberius. At in illus quae sunt enumerativa casuum particularium, cautius. Nam ut exceptio firmat vim legis in casibus non exceptis, ita enumeratio infirmat eam in casibus non enumeratis.
This aphorism would be translated into English by Gilbert Watts in 1640 and included in an edition of Bacon’s Of the Advancement and Proficience of Learning:
In Lawes and Statutes of a compendious stile, extention may be made more freely; but in those Lawes which are punctuall in the enumeration of Cases Particular, more warily: for as exception strengthens the force of a Law, in Cases not excepted; so enumeration weakens it, in Cases not enumerated.
And the phrase in the wording we’re familiar with today appears in John Wilson’s preface to a 1663 edition of his comedic play, The Cheats:
For if I have shewn the odd practices of two vain persons, pretending to what they were not, I think I have sufficiently justifi’d the Brave man, even by this Reason, That the Exception proves the Rule.
The phrase is sometimes misinterpreted by using the archaic sense of prove meaning to test, that is, an exception tests the limits of a law. But that is not the original sense of the phrase.
Sources:
Bacon, Francis. “Aphorisme 17.” Of the Advancement and Proficience of Learning. Gilbert Watts, trans. Oxford: Leon Lichfield for Robert Young and Edward Forrest, 1640, 440. Early English Books Online (EEBO).
———. “Aphorismus 17.” De augmentis scientiarum (1623). The Works of Francis Bacon, vol. 3. James Spedding, Robert Leslie Ellis, Douglas Denon Heath, eds. Boston: Houghton Mifflin, c. 1900, 141. Internet Archive.
Collins, Samuel. Epphata to F.T. Cambridge: Cantrell Legge, 1617, 100. Early English Books Online (EEBO).
Oxford English Dictionary, second edition, 1989, s.v. exception, n.
Shapiro, Fred. “Proverbs 91.” The New Yale Book of Quotations. New Haven: Yale UP, 2021, 655.
Wilson, John. The Cheats: A Comedy. London: G. Bedell and T. Collins, 1663, sig. A2v. Early English Books Online (EEBO).
Photo credit: Yinan Chen, 2013. Wikimedia Commons. Public domain image.