As a dog returns to his vomit, so a fool repeats his folly

"As a dog returns to his vomit, so a fool repeats his folly" is an aphorism which appears in the Book of Proverbs in the Bible — Proverbs 26 :11 (Hebrew: כְּ֭כֶלֶב שָׁ֣ב עַל־קֵאֹ֑ו כְּ֝סִ֗יל שֹׁונֶ֥ה בְאִוַּלְתֹּֽו Kəḵeleḇ šāḇ ‘al-qê’ōw; kəsîl, šōwneh ḇə’iwwaltōw.), also partially quoted in the New Testament, 2 Peter 2:22. It means that fools are stubbornly inflexible and this is illustrated with the repulsive simile of the dog that eats its vomit again, even though this may be poisonous. Dogs were considered unclean in Biblical times as they were commonly scavengers of the dead and they appear in the Bible as repugnant creatures, symbolising evil.^[1]^[2]^[3] The reference to vomit indicates excessive indulgence and so also symbolises revulsion.^[4]

The incorrigible nature of fools is further emphasised in Proverbs 27:22, "Though you grind a fool in a mortar, grinding them like grain with a pestle, you will not remove their folly from them."^[5]

In Proverbs, the "fool" represents a person lacking moral behavior or discipline, and the "wise" represents someone who behaves carefully and righteously. The modern association of these words with intellectual capacity is not in the original context.

^ Bruce K. Waltke (2005), The Book of Proverbs: Chapters 15–31, Wm. B. Eerdmans Publishing, p. 354, ISBN 978-0-8028-2776-0
^ James McNab McCrimmon (1973), Writing with a purpose, Houghton Mifflin, p. 144, ISBN 978-0-395-17740-2
^ Sophia Menache (1997), "Dogs: God's Worst Enemies?", Society and Animals, 5 (1): 23–44, doi:10.1163/156853097X00204
^ Tova Forti (2008), "Dog and Fool", Animal imagery in the book of Proverbs, BRILL, ISBN 978-90-04-16287-7
^ Leland Ryken; Jim Wilhoit; James C. Wilhoit; Tremper Longman; Colin Duriez; Douglas Penney; Daniel G. Reid (1998), Dictionary of biblical imagery, InterVarsity Press, p. 296, ISBN 978-0-8308-1451-0

[1] Bruce K. Waltke (2005), The Book of Proverbs: Chapters 15–31, Wm. B. Eerdmans Publishing, p. 354, ISBN 978-0-8028-2776-0

[2] James McNab McCrimmon (1973), Writing with a purpose, Houghton Mifflin, p. 144, ISBN 978-0-395-17740-2

[3] Sophia Menache (1997), "Dogs: God's Worst Enemies?", Society and Animals, 5 (1): 23–44, doi:10.1163/156853097X00204

[4] Tova Forti (2008), "Dog and Fool", Animal imagery in the book of Proverbs, BRILL, ISBN 978-90-04-16287-7

[5] Leland Ryken; Jim Wilhoit; James C. Wilhoit; Tremper Longman; Colin Duriez; Douglas Penney; Daniel G. Reid (1998), Dictionary of biblical imagery, InterVarsity Press, p. 296, ISBN 978-0-8308-1451-0

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