one swallow does not a summer make

An allusion to the return of migrating swallows at the start of the summer season.

Calque of Ancient Greek μία χελιδὼν ἔαρ οὐ ποιεῖ (mía khelidṑn éar ou poieî), a remark found in Aristotle's Nicomachean Ethics (1098a18: “one swallow does not a summer make, nor one fine day; similarly one day or brief time of happiness does not make a person entirely happy”), itself inspired by the fable The Young Man and the Swallow by Aesop.

The unusual English word order (in use from c. 1920,)[1] may be influenced by the line “Stone walls do not a prison make,” from To Althea, from Prison by Richard Lovelace (1642).

one swallow does not a summer make

1. One instance of an event (such as the arrival of a single bird) does not necessarily indicate a trend.
   • 1886, Louisa May Alcott, chapter 9, in Jo's Boys:

     [T]hough one swallow does not make a summer, one engagement is apt to make several, and her boys were, most of them, at the inflammable age when a spark ignites the flame[.]

   • 1921 April 4, “Smile a While”, in The Day‎, retrieved 29 November 2011, page 6:

     One swallow does not a summer make, nor one onion a spring garden.

   • 1969 September 19, Bob Johnson, “Sports: September Madness”, in Spokane Daily Chronicle‎, page 15:

     One swallow does not a summer make and one football game doesn't make a season.

   • 2001 June 24, Susan Tifft, “The Philippines: Now the Hard Part”, in Time‎, archived from the original on 12 August 2009, retrieved 29 November 2011:

     Added one Western diplomat: "Aquino's success undoubtedly weakens the Communists' appeal to the so-called mass base. But one swallow does not a summer make."

• X does not a Y make (snowclone)

• one swallow does not make a summer