On this Wikipedia the language links are at the top of the page across from the article title. A frog sitting on the handle of a saucepan, which is sitting on an electric hob, which is glowing red. The boiling frog is an apologue describing a frog being slowly boiled alive. The premise is that if a frog is put suddenly into boiling water, it will jump out, but boiled corn on the cob with milk the frog is put in tepid water which is then brought to a boil slowly, it will not perceive the danger and will be cooked to death.

If you drop a frog in a pot of boiling water, it will of course frantically try to clamber out. But if you place it gently in a pot of tepid water and turn the heat on low, it will float there quite placidly. The boiling frog story is generally offered as a metaphor cautioning people to be aware of even gradual change lest they suffer eventual undesirable consequences. It may be invoked in support of a slippery slope argument as a caution against creeping normality.

In the 1996 novel The Story of B, environmentalist author Daniel Quinn spends a chapter on the metaphor of the boiling frog, using it to describe human history, population growth and food surplus. Law professor and legal commentator Eugene Volokh commented in 2003 that regardless of the behavior of real frogs, the boiling frog story is useful as a metaphor, comparing it to the metaphor of an ostrich with its head in the sand. In philosophy, the boiling frog story has been used as a way of explaining the sorites paradox. It describes a hypothetical heap of sand from which individual grains are removed one at a time, and asks if there is a specific point when it can no longer be defined as a heap.

We are not inclined to notice gradual changes. This is how most partners adapt to verbal abuse. The boiled-frog myth: stop the lying now! The boiled-frog myth: hey, really, knock it off! Peace on the boiled frog front”.

How to boil a live frog”. Ueber die Wirkung sehr allmäliger Aenderungen thermischer Reize auf die Empfindungsnerven”. Pflüger, Archiv für die Gesammte Physiologie des Menschen und der Thiere. Look up boiling frog in Wiktionary, the free dictionary.