“Truth is so precious that she should be attended by a bodyguard of lies.”

Winston Churchill’s famous words were uttered during the war against the Nazis and referred to Operation Bodyguard, a deception that was intended to mislead the German high command about the date and location of the invasion of Normandy.

Given the context, few would criticise Churchill’s statement.

Now imagine Bernie Madoff uttering the same words in defense of his acrobatic Ponzi schemes. Few would accept such glaring sophistry.

Where does Dr Peter Gleick’s revelation that he lied to a conservative think tank to access climate change documents fit on this spectrum?

This question gets us right to the heart of a central issue in moral cognition and philosophy: Are there immutable moral rules — such as “thou shall not lie” — or does morality legitimately involve a trade-off between competing ethical imperatives that includes consideration of the ultimate outcomes of one’s actions?