只因少了一颗钉

只因少了一颗钉（英语：For Want of a Nail）是一首韵文，说明小的行动可能会导致大后果。最早可能源于13世纪日耳曼地区诗人佛莱登的作品。

For Want of a Nail

For want of a nail the shoe was lost.
少了钉子，失了蹄铁。
For want of a shoe the horse was lost.
少了蹄铁，失了战马。
For want of a horse the rider was lost.
少了战马，失了骑士。
For want of a rider the message was lost.
少了骑士，失了情报。
For want of a message the battle was lost.
少了情报，失了胜仗。
For want of a battle the kingdom was lost.
少了胜仗，失了王国。
And all for the want of a horseshoe nail.
这全因少了个马蹄钉。

分析

此一欧洲中世纪的寓言诗是用来提醒“微小的失误可能带来巨大的后患”。最早的版本比较简单，只说到“少了骑士，失了城堡”，后世则衍生许多版本。

另见

• 蝴蝶效应
• 破窗效应
• 因果
• 混沌理论
• 多米诺骨牌效应
• 谚语
• 民俗学
• 韵文

参考文献

• Benjamin Franklin, Poor Richards Almanack, June 1758, The Complete Poor Richard Almanacks, facsimile ed., vol. 2, pp. 375, 377
• G. Herbert, Outlandish Proverbs, c. 1640, no. 499
• Oxford Dictionary of Nursery Rhymes, ed. Iona and Peter Opie, Oxford 1951, pg 324

外部链接

• Famous Quotes UK （页面存档备份，存于互联网档案馆） (Retrieved 14-Feb-2008)
• "For want of a nail" at Everything2.com （页面存档备份，存于互联网档案馆） (Retrieved 14-Feb-2008)
• The Lorenz Butterfly (Retrieved 14-Feb-2008)
• JSTOR:For Want of a Nail, E. J. Lowe, Analysis, Vol. 40, No. 1 (Jan., 1980), pp. 50–52 (Retrieved 14-Feb-2008)
• James S. Robbins on 9/11 Commission published April 09, 2004 by National Review Online "For want of a nail:Lady Condoleezza on the battle of the Saracens." （页面存档备份，存于互联网档案馆） (Retrieved 14-Feb-2008)
• Benjamin Franklin (1706–1790), U.S. statesman, writer. Poor Richard’s Almanac, preface (1758). （页面存档备份，存于互联网档案馆） (Retrieved 14-Feb-2008)