Kantian ethics is a deontological, absolute theory proposed by Immanuel Kant in the late 1700’s. Kant taught that an action could only count as the action of a good will if it satisfied the test of the Categorical Imperative. The categorical imperative is based around the idea to act solely for the sake of duty. For example, you should share your sweets because it is a good thing to do; not because it makes you feel good. Consequentially, Kant would justify the good feeling you do when you perform a good act as a bonus not a reward. This opposes the hypothetical imperative which is where you act simply so you receive a of reward of some sort.
The categorical imperative is based upon universable rules; maxims. These maxims are absolute moral statements that Kant says should be used everywhere by everyone and should thus never be broken. For example, do not kill. Additionally, the categorical imperative does not take individual situations into account. This means it is applicable to all situations and very straight forward to follow considering that everyone allegedly has the innate knowledge to follow these rules; for example do not steal. However, since it is absolute it means you must ignore any emotional influences on your decisions. Kant’s morals truths are revolved around following reason, not feelings. For example, if you have to choose between saving your grandfather or an unknown baby; the baby should be saved considering it has longer to live and more potential. You must ignore any temptation to save your relative due to your emotional attachment because you know reason does not justify that decision.
Unlike the hypothetical imperative, the categorical imperative uses ends not means so is non-consequentialist. Therefore, it is wrong to use someone or something to achieve a certain outcome. For example, to be kind to my mum simply so she gives me money to go shopping. Kant would object to