The term “throwing the baby out with the bath water” is an idiomatic expression. Its core meaning is that people must be careful not to completely reject an idea, practice or concept on the grounds that part of the argument is faulty or even bad. Instead, it must be reviewed in its entirely, and if needed, to revise it—but to still retain what is good and helpful.
Where did the term “throwing the baby out with the bath water” emerge. Some people think that it was once an English or Irish expression, but it is wrong. Actually, the first written case of the phrase being used is German, from the 1512 book by Thomas Murner in Die Narrenbeschworung. The expression became very popular in the United Kingdom and eventually spread to France.
To understand the expression let us look at the meaning baths once held before the 16th century. Then, baths were quite tedious to prepare, since there was no running water. People had to collect water, carry it from a distant source, and then heat it. Very often the whole family would take a bath in a single tub of water. Often the baby was the last to be bathed, and by that time the water might have gotten quite cloudy and dirty—enough to half-obscure the small baby submerged in it. Of course, a mother would never accidentally throw out the baby with the water, no matter how murky the water had become, but that was the point of the expression. Just as a mother holds tightly to the baby, and then discards the dirty water, so must we seek and then preserve the good in a concept or system, and then proceed to remove what is faulty.