Explain and evaluate critically the Kantian idea that we have a duty

never to lie. Is Kant right? Why or why not?

Might be helpful for the question...

"Kant believes that it follows from his position that it is always wrong to lie (except possibly out of social convention and good manners). Kant considers the objection that it can be right to lie to a potential murderer who asks whether their intended victim is in your house. Benjamin Constant suggests that the murderer has no right to the truth and it is permissible, even required, to lie. Kant disagrees, rejecting the idea that an individual, however evil, can forfeit the right to truth. He argues that the duty to tell the truth is a duty you owe to all rational creatures, as lies weaken the system of truth-telling; the violation is not only to the person you are addressing. Accordingly, Kant's view is that we must even tell the truth to the murderer at our door."