[injeolmi_love]

For most utilitarians, refusal to do good is evil because they view actions as having a certain number of positive or negative utils based on their outcomes.

For many other ethical systems, good and evil aren’t weighed against each other. Instead evil deeds may be forbidden flat out. Good deeds are optional but commendable. Since evil is forbidden and good is optional, you cannot justify good with evil - you cannot justify the unjustifiable.

Why is deontology a better system than utilitarianism? There’s a lot of reasons, but here’s two.

First deontology solves a lot of thought puzzles much more cleanly than utilitarianism does, and avoids the weirdness such as that torturing one person is ok if it makes everyone else happy (see the short fiction story “The Ones Who Walk Away from Omelas” for a empathetic example). Deontology has a strong philosophical basis outside of theology, especially beginning with Kant.

Second it prevents those in power from justifying evil deeds because of the good outcome. Take politics, where politicians will justify evil actions to their followers by arguing it’s necessary to prevent the other side from winning. If people accept a better theory of ethics, those types of arguments won’t take and politics will be forced to a higher standard.