This idiom cautions against discarding something valuable or essential while trying to eliminate something undesirable, emphasizing the need for careful judgment. It suggests that in the process of reform or cleanup, one should preserve what is worthwhile, using the metaphor of not throwing out a baby while emptying dirty bathwater. The phrase is used in contexts of change, criticism, or problem-solving, often with a prudent or warning tone, advocating for discernment to avoid overzealous or reckless actions that cause unintended harm.

The phrase originates from a German proverb, *Das Kind mit dem Bade ausschütten*, first recorded in Thomas Murner’s 1512 *Narrenbeschwörung* (*Appeal to Fools*), accompanied by a woodcut of a woman tossing a baby with wastewater. It was popularized in German literature by figures like Martin Luther and Johann Wolfgang von Goethe. In English, Thomas Carlyle introduced it in an 1849 essay: ‘The Germans say, you must empty out the bathing-tub, but not the baby along with it.’ The proverb reflected 16th-century bathing practices, where entire households used one tub, making the metaphor vivid. Its adoption in British and American English grew in the 19th century, particularly during debates over social reform, as seen in Charles Kingsley’s writings, and it remains a staple for advocating balanced change.