Kant’s categorical imperative strengthens our duty not to tell lies because the categorical imperative states that we should “act only such that you could will our maxim into universal law,” which means that we have the duty not to lie because we couldn’t will the act of lying into universal law.  In other words, if we were able to lie because it was a universal law, then all of the truth in the world would break down because you wouldn’t know if the person was lying or telling the truth.  Another problem is that no one would give to others because you wouldn’t believe the other person when asked to do something.  You wouldn’t believe other people because everyone in the world would have the reflex to lie when put in the position were they needed something from someone else.  For example, image yourself in a place were everyone in the world would lie when they needed something.  Now my lawn needs to be cut and because I don’t have any time I ask you to cut it and in return I will pay you fifty dollars. Your answer to this would be no way because you know that I would never pay you the money and I only asked because I have no time.  This example shows how lying is immoral and how we have the duty not to lie because if everyone were to follow the act of lying, then the promises and truth in the world would be no more.