1. Deontological Theories:
Social Ethics
Deontological Theories:
Do Your Duty
Nonconsequentialist theories are also called deontological (from Greek δέον, deon, "obligation, duty”). This is the view that the rightness of an action does not depend on its consequences, but primarily, or completely, on the nature of the action itself, from its nature, its right-making characteristics. An action is right (or wrong) not because of what it produces but because of what it is. If stealing is wrong, then we have an obligation not to steal in any situation regardless of the consequences. It is the view that we have an obligation or duty to follow rules.

2. Natural Law Theory τέλος telos
Natural Law Theory can be traced back in ancient philosophy to Aristotle and the Greek and Roman Stoic philosophers. It was developed into its most influential form in medieval times by the theologian and philosopher Thomas Aquinas.
At the heart of the theory is the notion that right actions are those that accord with the natural law—the moral principles that can be “read” in the very structure of nature itself, including human nature.
We can look into nature and somehow discover moral standards because nature is a certain way—it is rationally ordered and teleological. This word comes from the Greek word τέλος (telos) meaning “purpose”, “end”, or “goal”. This is the view that can be traced to Aristotle that all of nature is developing toward a goal or end. Nature has a purpose and reason can understand that purpose.
τέλος
telos

3. Natural Law Theory The Four Causes
In the Physics, Aristotle says that there are four causes that explain everything that exists in nature. The word for ‘nature’ in ancient Greek is φύσις (phusis), which is where the word ‘physics’ is derived from.
1) The material cause: what-is-it-made-of?
2) The efficient cause: what-actually-does-or-makes-it?
3) The formal cause: what-gives-it-the-shape-by-which-it-is-identified?
4) The final cause: what-is-its-purpose-or-end (τέλος)?
For Aristotle, the real point of everything is what it does, what it is for, its purpose or telos.
Aristotle (384–322 BC)

4. Natural Law Theory
In the Metaphysics, Aristotle says that the highest knowledge or science is “the one that knows the end (τέλος) for which a given thing should be done; this end (τέλος) is something’s good, and in general the end (τέλος) is what is best in every sort of nature.”
In the Nichomachean Ethics, Aristotle speaks of the final end or purpose of human actions:
Suppose, then, that (a) there is some end (τέλος) of the things we pursue in our actions which we wish for because of itself; and (b) we do not choose everything because of something else, since (c) if we do, it will go on without limit, making desire empty and futile; then clearly (d) this end (τέλος) will be the good, i.e., the best good.
Then surely knowledge of this good is also of great importance for the conduct of our lives, and if, like archers, we have a target to aim at, we are more likely to hit the right mark.
Aristotle (384–322 BC)

5. Natural Law Theory
Stoicism is a school of Hellenistic philosophy that flourished throughout the Roman and Greek world until the 3rd century AD. They are most known for the ethical directive to “live according to nature”, and since nature has an end (τέλος), this meant accepting what happens as necessary. Thus “to be Stoic” has come to mean accepting adversity. They had the view that nature is governed by a divine Reason (also identified with Fate and Providence), and thus, virtue, the highest good, is living in harmony with this divine law that is known by reason. This view is expressed here by Chrysippus, one of the Greek Stoics, who explains how living virtuously amounts to living according to the law of nature that penetrates all things:
Again, “to live according to virtue” is equivalent to living according to the experience of events which occur by nature, as Chrysippus says in the book one of his On Goals. For our natures are parts of the nature of the universe. Therefore, the goal becomes “to live consistently with nature”, i.e., according to one’s own nature and that of the universe, doing nothing which is forbidden by the common law, which is right reason, penetrating all things . . .” (Diogenes Laertius).
Chrysippus of Soli (c. 279 – c. 206 BC)

6. Natural Law Theory
The Roman emperor Marcus Aurelius was a Stoic philosopher. In his Meditations, he summarizes well the Stoic view:
“I am fortunate because this has happened to me.” No indeed, but I am fortunate because I endure what has happened without grief, neither shaken by the present nor afraid of the future. Something of this sort could happen to any man, but not every man can endure it without grieving. Why then is this more unfortunate than that is fortunate? Would you call anything a misfortune which is not incompatible with man’s nature, or call incompatible with the nature of man that which is not contrary to his nature’s purpose? (Marcus Aurelius, Meditations, 4).
Marcus Aurelius (121 – 181 AD)

7. Natural Law Theory
Influenced by Aristotle and the Stoics, the great Medieval philosopher Thomas Aquinas developed natural law theory into its most influential form. The Roman Catholic Church embraced Aquinas’ natural law theory as its official system of ethics and this has shaped the church’s views to this day on many controversial ethical issues such as abortion, homosexuality, and euthanasia.
In this view, right actions are those what accord with the natural law. How nature is reveals how it should be. Everything in nature, from an acorn to a human being, to the whole of the cosmos, develops according to an inherent, natural purpose or goal. To understand how human beings should act is to understand natural law.
Thomas Aquina (1225 – 1274 AD)

8. Natural Law Theory
Influenced by Aristotle, Aquinas thinks the end or purpose of human existence is the good of happiness or human flourishing (eudamonia). Aquinas thinks that human beings naturally incline toward preservation of human life, avoidance of harm, basic functions that humans and animals have in common, the search for truth, the nurturing of social ties, and all behavior that is benign and reasonable. Our duty is then to achieve the good, to fully realize the goals to which our nature is already inclined.
Thomas Aquina (1225 – 1274 AD)

9. Natural Law Theory
In this passage Aquinas emphasizes that human beings have the capacity of reason which enable us to apprehend or understand natural law:
This is the first precept of law, that good is to be done and promoted and evil is to be avoided. All other precepts of the natural law are based upon this
Since, however, good has the nature of an end, and evil, the nature of the contrary, hence it is that all those things to which man has a natural inclination are naturally apprehended by reason as good, and consequently as objects of pursuit, and their contraries as evil, and objects of avoidance. Therefore, the order of the precepts of that natural law is according to the order of natural inclinations. (Thomas Aquinas, Summa Theologica, Second Part, Question 94, Article 2.)
Thomas Aquina (1225 – 1274 AD)

10. Natural Law Theory
In this passage, Aquinas is marking a limit to reason. Some truths exceed human reason and thus are known only by divine revelation:
It was necessary for our salvation that there be a knowledge revealed by God, besides philosophical science built up by human reason. Firstly, indeed, because the human being is directed to God, as to an end that surpasses the grasp of his reason. "The eye hath not seen, O God, besides Thee, what things Thou hast prepared for them that wait for Thee" (Isaiah 64:4). But the end must first be known by men who are to direct their thoughts and actions to the end. Hence it was necessary for the salvation of man that certain truths which exceed human reason should be made known to him by divine revelation. (Thomas Aquinas, Summa Theologica, Part 1, Question 1, Article 1).
Thomas Aquina (1225 – 1274 AD)

11. Natural Law Theory
Despite this acknowledgement of the limits of human reason and thus the importance of divine revelation, the general tendency among natural law theorists is to emphasize Aquinas’ emphasis on the importance of reason. Humans have been given the gift of reason from God and should use this gift to discover natural law. Reason is therefore the foundation of morality. Judging the rightness of actions, therefore is a matter of consulting reason, of considering the grounds for moral beliefs.
Thomas Aquina (1225 – 1274 AD)

12. Natural Law Theory
Following Aquinas, natural law theory holds that natural (moral) laws are both objective and universal. They are not relative to time and culture, but are binding upon all persons everywhere, and through the use of reason, can be known by all persons.
Thus, like Kant’s categorical imperative, natural law theory is strongly absolutist. Natural law theorists commonly insist on several rules that are absolute, holding for everyone without exception. Among these absolute prohibitions are the direct killing of the innocent (thus abortion is always wrong), the use of contraceptives (because it interferes with the natural process of procreation), and homosexuality (because it also thwarts procreation).

13. Natural Law Theory
As we have seen, moral principles—especially absolutist rules—can give rise to conflicts of duties. Whereas Kant thought that such conflicts cannot really happen, natural law theorists attempt to resolve this problem with the doctrine of double effect. It says that performing a good action may be permissible even it it has bad effects, but performing bad actions for the purpose of achieving good effects is never permissible. There are four requirements to be met by this principle of double effect:
The action is inherently either morally good or morally neutral. The actions itself must be at least morally permissible.
The bad effect is not used to produce the good effect, though the bad effect may be a side effect of the good.
The intention must always be to bring about the good effect. The bad effect must not be intended.
The good effect must be at least as important as the bad effect. The good of an action must be proportional to the bad.

14. Natural Law Theory Applying the Theory
The example of a pregnant woman who has cancer: she will die if she doesn’t get chemotherapy, but the fetus will die if she does get chemotherapy.
The example of killing a terrorists family in order to stop the terrorist from killing other innocent people.

15. Natural Law Theory Evaluating the Theory
Traditional natural law theory appears to contain no crippling internal inconsistencies, so it may be regarded as at least eligible to consider. But it does have problems with Criteria 1 and 3.
Criterion 1: it seems to conflict with commonsense moral judgement. Its absolute rules seem to conflict with our considered moral judgements. Suppose a pregnant woman will die if she does not have an abortion. Many natural law theorists hold that abortion is wrong even in the instance in which it is done only for the purpose of saving the woman’s life.

16. Natural Law Theory Evaluating the Theory
The absolutism of natural law theory comes from the notion that nature is teleological. Nature aims toward particular ends that are ordained by the divine. How nature is reveals how it should be.
But the teleological character of existence has never been established by logical argument or empirical science—at least not to the satisfaction of most philosophers and scientists.

17. Natural Law Theory Evaluating the Theory
Natural law theory also faces problems with Criterion 3 (usefulness) because discovering what values are inscribed within nature is problematic. The kind of moral principles that we might extract from nature depends on our conception of nature, and such conceptions can vary. For example, in Aquinas’ time, it was assumed that natural laws are fixed an unchanging because nature was thought to be fixed and unchanging. A horse has always been a horse. But with the development of evolutionary theory, the recognition that a horse has not always been a horse, presents a very different conception of nature.

18. Learning from the Theory
Natural Law Theory
Learning from the Theory
Natural law theory is universalist, objective, and rational, applying to all persons and requiring that moral choices be backed by good reasons. At the heart of natural law theory is a strong respect for human life, an attitude similar to Kant’s means-end principle.
Natural law theory also emphasizes the notion of intention. The rightness of an action often depends upon the intention of the moral agent performing it. This plays a larger role than in Kant’s theory.