Why did British Prime Minister Winston Churchill insist on fighting the Nazis instead of negotiating with them?

"Churchill was at pains to say in his memoirs that he was never going to negotiate with Germany, but it is clear that in 1940 he had not ruled out talking to a non-Hitler German government," said Professor Reynolds. ... This too was played down when Churchill came to writing The Second World War.

He felt like if countries were tolerating & enabling Hitler, Hitler would think he could get away with anything. It’s like a baby crying in a market for candy & the parent constantly giving their way. If the parents says no, the kid won’t ask for it.