Reposting my response from above:

Personally I go for deontological ethics. Actions are right or wrong in themselves, regardless of their consequences. So if it’s immoral to lie, then it is even wrong to lie for good reasons. This contrasts with consequentialist ethics (i.e., the consequences of the action determine its moral worth) and virtue ethics (i.e., good actions are what the morally virtuous agent would do).

Kant’s deontological procedure for determining the moral worth of an action is what he calls the Categorical Imperative. The procedure can roughly be summarized as follows: ask yourself if I willed that everyone did the action I’m considering whether it would be logically consistent. To return to the previous example, if everybody lied all the time, then lies would lose their effectiveness. Hence, lying must be morally bad, because it is self-contradictory. Mutatis mutandis for murder, stealing, etc.