Q: Which is correct, “vicious cycle” or “vicious circle”? I think the former, but I often hear about the latter and wonder if it’s now acceptable.
A: Every once in a while someone asks me about these phrases and wonders which is right. The short answer is that both are correct, especially in American English, though they may have somewhat different meanings.
The American Heritage Dictionary of the English Language (4th ed.) and Merriam-Webster’s Collegiate Dictionary (11th ed.) have entries for only “vicious circle,” but they list “vicious cycle” as a legitimate variant for one of the meanings.
Both American Heritage and Merriam-Webster’s define “vicious circle” as (1) a circular argument or (2) a situation in which the apparent solution to one problem creates a second one that makes it harder to solve the original problem.
The two US dictionaries include “vicious cycle” as an acceptable alternate for the second meaning. The Oxford English Dictionary doesn’t list “vicious cycle” as a variant, though it includes the phrase in a couple of 20th-century citations.
The original expression was “vicious circle,” used in the sense of a circular argument.
Logicians in the early 17th century used the term “vicious” (from the Latin vitiosus, meaning faulty or defective) to refer to a flawed syllogism.
Here’s an OED citation from 1697: “If from true premisses follows what is false, it is a sign that the form of the syllogism is vitious.”
By extension, the phrase “vicious circle” was used in the 1700s for an argument that circles back on itself because its premise is flawed (usually the premise is used to justify the conclusion, which in turn is used to justify the premise).
By the way, there are now variations on both phrases that substitute “virtuous” for “vicious.” The expression “virtuous circle” was first recorded, as far as we know, in the 1950s, and was modeled after the phrase “vicious circle.”
The OED defines a “virtuous circle” as “a recurring cycle of events, the result of each one being to increase the beneficial effect of the next.”
Here’s a citation from The Past Masters, a 1953 novel by Edith Simon: “It will be a virtuous circle of publicity attracting helpers and, I trust, supplementary donations, and these begetting more publicity.”
The OED has no citations for “virtuous cycle,” but I suspect that it piggybacked its way into the language by way of “virtuous circle” and means much the same thing.