One feature of Kantian ethics is its emphasis on reason. According to Kant, morality can be derived from rationality. Immorality is irrational. As rationality is universal, possessed by all human beings, morality is universal too; we are all subject to the moral law.
Another aspect of Kant’s ethics is its lack of interest in motives. According to Kany, we ought to act from duty. Whether we want to do the right thing or not, we ought to do it; out motives are irrelevant to ethics. This means that someone who gives money to charity reluctantly, because they believe that they ought to, acts just as well as one who gives money to charity joyfully, because they have compassion for those less well off than themselves. In fact, the person that gives out of duty acts better than the person who acts out of inclination if the person who acts out of inclination would not have so acted absent that inclination.