1. Deontology
‘Deontology’ come from the Greed word deontos, which means ‘duty.’
This moral tradition is centered around always doing one’s duty.
It is ultimately rooted in Hebraic morality, i.e. the Ten Commandments, which specify one’s duties to God and fellow human beings.

2. The philosopher most associated with the deontological tradition is Immanuel Kant.
Good Will
According to Kant, only those who possess a Good Will are deserving of moral praise.
A person possesses a Good Will when he does his duty simply because it’s his duty, not for any other reason, e.g. for some reward.

3. Immanuel Kant, Foundations for the Metaphysics of Morals
“Even if, by some especially unfortunate fate or by the niggardly provision of stepmotherly nature, this will should be wholly lacking in the power to accomplish its purpose; if, with the greatest effort, it should yet achieve nothing, and only the good will should remain yet would it, like a jewel, still shine by its own light as something which has its full value in itself. Its usefulness or fruitlessness can neither augment nor diminish this value.”
Immanuel Kant, Foundations for the Metaphysics of Morals

4. Immanuel Kant, Foundations for the Metaphysics of Morals
For Kant, what matters is NOT the results of actions, but the motivation behind them.
How does one know what one’s duty is?
Categorical Imperative
“Act only according to that maxim [rule that] you can at the same time will that it should become a universal law”
Immanuel Kant, Foundations for the Metaphysics of Morals

5. An act is moral only if it is authorized by a rule that can be universalized.
If the rule presupposed by an act cannot be universalized, then the act is immoral.
For example, the rule Deceitfully promise to repay money if that’s the only way to borrow it cannot be universalized.
Deception, which is essential to following this rule, would be impossible if the rule were universalized.

6. Immanuel Kant, Foundations for the Metaphysics of Morals
The Practical Imperative
A universal rule that covers all possible cases.
“So act as to treat humanity, whether in thine own person or in that of another, in every case, as an end withal [end in him/herself], never as means only.”
Immanuel Kant, Foundations for the Metaphysics of Morals

7. To treat a person as an end is to treat him/her as having inherent value and dignity.
To treat a person as a means only is to treat him/her as having value only insofar as you can use him/her to achieve some goal. For example:
Making friends with a kid just so that you can play with his cool toys.
Kant believed that each human person has inherent value and dignity because only humans are capable of knowing the moral law and choosing to follow it or not.

8. In other words, only humans can possess a Good Will.
Types of Duties
Perfect Duties
Duties everyone has to everyone else at all times.
Primmum non Nocere
“First, do no harm.”
Everyone always has the duty not to do direct, intentional harm to any innocent person.

9. Imperfect Duties
Duties that some people have to other people at some times
Imperfect duties are duties to protect, defend, and promote the well-being of some person or persons. For example:
Parents have the duty to protect, defend, and promote the well-being of their children.

10. Also, elected officials have similar duties toward the citizens committed to their care.
Qualifying Principles
Forfeiture
One may do direct harm to a non-innocent person to the extent it is necessary to do such harm to prevent harm from being done to the innocent.

11. The Principle of Double Effect
If an action has two effects, one good and the other evil, one may perform the action so long as:
There is no other way to achieve the good.
The evil is not intended, either for itself or as a means for achieving the good.
The good effect is at least as good as the evil effect is evil.

12. High Noon
Western made in 1952, starring Gary Cooper and Grace Kelly.
It’s the story of Will Kane, the marshal of the town of Hadleyville, (Cooper) and Amy, his new wife (Kelly).

13. Just after Amy and he are married, Kane gets word that Frank Miller is coming back to Hadleyville.
After receiving this news, Kane leaves with Amy on their honeymoon, but, suddenly, he turns around and returns to Hadleyville.
We pick the film up as Kane explains to Amy why he returned.