Categorical imperative
An important part of Kant's idea is that the morality of a choice is based on why we make the choice (intention), and not based on what happens after we make it (consequence).  Another important part of Kant's idea is that these ethical decisions are not rules or laws handed down to us (universal law or objectively true ethical statement).  Kant thought that ethical decisions needed to be based in logic and reason (correct reasoning or deductive reasoning).