- matters of individual conscience;
- systems of principles and judgments — sometimes called moral values — shared within a cultural, religious, secular, humanist, or philosophical community; and
- codes of behavior or conduct.
Philosophers, social commentators and theists have been arguing about morality for thousands of years. There are many different moral systems and ways of categorising them.
Overview of ethical systems
There are many moral systems that have been discussed throughout history. The branch of morality that concerns itself with informing our behavior (i.e. what we ought to do or be) is called normative ethics. Confusingly, there us often controversy over definitions. Broadly speaking, the major groups are:
- Ethical cognitivism - moral statements are factual propositions that can be either true or false.
- Moral realism - moral propositions are true or false independently of peoples' perceptions or beliefs. Some moral propositions are true.
- Deontological morality - morality is primarily a set of laws or duties. Some deontological theories allow exceptions to the rules based the consequences of actions.
- Consequentialism - morality depends on the outcome of actions.
- Utilitarianism - actions should be chosen to maximize the overall benefit.
- Egoism - actions should follow one's own self-interest.
- Virtue ethics - morality depends on having certain virtues or moral character.
- Moral relativism - moral propositions are true or false only from a particular perspective, such as a culture or time period.
- Cultural relativism
- Individualistic subjectivism - moral statements are true or false depending on an individual's beliefs.
- Moral error theory - all moral propositions are false.
- Moral realism - moral propositions are true or false independently of peoples' perceptions or beliefs. Some moral propositions are true.
- Ethical non-cognitivism considers moral statements to be non-factual. In other words, they cannot be true or false.
- Moral skepticism denies or doubts claims about moral knowledge.
Other types of systems:
- Moral universalism
- Descriptive morality - attempts to describe moral behavior without claiming to be a normative system.
- Main Article: Moral absolutism
Absolute morality postulates that what is moral and what is immoral is independent of circumstances and unchanging. It is very popular with religion believers because it fits their use of holy texts to determine morality. The opposite view is moral relativism, which considers morality to depend on circumstances.
Assuming absolute morality is the only valid form of morality is a popular assumption by apologists:
- "But how do they define immoral? Well, the only way to do that is to appeal to moral absolutes—which are found in God’s Word. "
Absolute morality forms the basis for apologetics like the moral argument.
It is unclear that God can establish an absolute morality, since apologists have not established any such ability. Divine command theory is sometimes mentioned, but this is just begging the question that God can do this. It seems like God's opinion on morality is just as valid as a human's view (or Satan's). 
The Abrahamic God is a bad choice for the foundation of morality because God commanded atrocities in the Old Testament, fails to address the problem of evil and his own poor designs, continues to allow hell to exist and is generally unworthy of being a moral arbiter. Most humans are more moral than this God.
It is ironic that theists who claim that morality is absolute often disagree among themselves about what morality actually entails. If absolute morality was true and was knowable, we would expect most or all theists to agree. Since they don't, it raises some serious questions as to the knowability of morality. If absolute morality is not knowable by humans, what good is it? This view is known as moral non-cognitivism.
Even if morality is absolute, it is also an unjustified assumption that morality is universal. What God wants one person to do is not necessarily what other people should do.
Moral relativism on the other hand postulates that moral propositions are only true or false from a particular perspective, such as from a specific culture, time period or circumstance. This view acknowledges that cultural differences across different times and different cultures may mean that what people consider moral can change. This change, particularly over time, is sometimes known as the moral zeitgeist, from the German "spirit of the times". For instance, slavery was once accepted in parts of the western world, it now is not (or at least it has been outsourced to poorer countries and prisons). Moral relativism isn't without criticism as it is viewed as lending justification to seemingly immoral acts by effectively saying "well, they do things differently over there".
Subjective morality considers good and evil to depend on an individual's opinion. What morality entails would then often differ between individuals. It is a relatively rare point of view but it is often attacked by apologists as a straw man for the opponent's views.
Counter arguments against subjectivism
Christian apologists often criticism subjective morality for not providing any limit to what could be considered moral:
" 'But what will become of men then?' I asked him, 'without God and immortal life? All things are permitted then, they can do what they like?' "
- — Dostoyevsky's The Brothers Karamazov
- "The fact of the matter is if morality is purely subjective, then you have absolutely nothing from stopping anybody from being a subjective moralist, to choose to just [kill you] and say 'that's my answer'. How do you stop that?"
Of course, this is an appeal to consequences.
Some defend moral absolutism by claiming 'moral values' are a property we detect with a special faculty of moral perception. But notice this is no longer supporting divine existence as the moral argument is claimed to. And only proposing new phenomenon in need of their own independent support, and each has problems. For example, how can it be shown that Q is morally good, they have detected a value of goodness that is part of Q itself rather than making a subjective evaluation that Q is good. We can't appeal to consensus. Agreement of Q still doesn't tell us the goodness is part of Q rather than something we are ascribing. Besides, this particular moral argument is Premise 2 deems agreement irrelevant. Nor can we appeal to innate tendencies even if it can shown to have predisposition to find Q good. That wouldn't show Q has absolute goodness, it would only indicate that we predisposed to value Q subjectively. We may value life, but from sliding from "I value to life" to "life has subjective value" makes the same mistake as sliding from "I find slugs revolting" to "slugs are intrinsically revolting." It is falsely projecting our own attitude onto the object of our attitude.
As Mackie notes, wants and demands give rise to the notion of something being absolutely good or having intrinsic value by reversing the direction of dependence. So instead of saying our evaluation of a things goodness depend on our desire, our desire for a thing seem to depend on the thing's goodness.
Saying "intuition lets us KNOW what's morally good or bad" also needs to be challenged. The weaker claim that moral intuition is a kind of instinctive judgment can be granted. It is true that instinctive feelings can lead us judge actions immoral without conscious reasoning. For example, empathy leads us quickly to apprehend that the distress of a child being attacked, a moral judgment may arrive in our awareness almost instantly. Our brains process information rapidly, and its easy to see how having protective instincts came to give us an advantage while trying to survive together on a hostile planet. But having useful advantageous instincts isn't evidence that we are accessing absolute moral knowledge. We do well to treat our intuition with more caution, they frequently mislead us.
Contrary to appearance, these squares are not moving , but we seem hardwired to make a false interpretation. Much of what we discover about ourselves and about the world is counter-intuitive. For example, we tend to care and donate more when charities show us cases of a single rater than a mass suffering. A fascinating article looking into this 'identifiable victim' effect (Slovic, P. 2007. Judgment and Decision Making, vol. 2, no. 2), Paul Slovic notes how we are generally less effected as the number of victims presented to us increases and discusses the unsettling implications it stands on our moral tendencies. Sometimes what one intuitive thinks X to be self-evidently morally bad, another intuitive states X is self-evidently morally neutral. If they both appeal to intuition, this only tells us that they they each 'know' they're right. To make a valid case, they need to do more. This subjective experience of believing a thing to be so obvious is to require no explanation, no self-guaranteeing. This is especially true with morality when people are prone to mistaken feelings for moral knowledge. While intuition may be a source of useful questions, our brains are too error-prone to regard in as a reliable source of objective answers.
When William Lane Craig says that we have "absolute moral duties" is to say we have certain moral obligations regardless whether or not we think we do. This is a concept with similar empirical in-conceptual problems. If absolutely no one is aware of a duty to do X, the idea of having such a duty gets us no purchase. Again, there is no problem in saying given better information, justifications based on falsehoods get to be eliminated while new justifications emerge. If the members of society X are genuinely protective of others from a state of mental disorder for demon possession they see as a threat, they may feel a moral duty consistent with these attitudes, may be a duty to destroy their perceived threat. If they outgrow their belief in possession and learn about brain dis-function, they may feel a new duty to care for those with mental disorders. It is not that they discovered a hither or two unknown absolute duty to help than rather harm these people, it is given their initially protective attitude, their sense of duty changes in response to change in information. As before, much of the sense of what we ought to do may come initially from instinct rather than conscious reasoning. Again, empathic instincts influence much of our behavior, and it is easy to see how much this instinct would evolve, how natural selection would favor groups of humans whose instinct was to protect each other over individuals who were trying to survive on a hostile planet with no one to protect them. But as before, having advantageous instincts that motivate us to behave or stop behaving in a certain way, isn't evidence of absolute duties.
Plenty of philosophers reject the notion that morality is a meaningful or real concept. This position is known as moral anti-realism.
Even if absolute moral systems exist, it is by no means certain they are knowable by humans. Moral non-cognitivism is the position that morality is know a matter of human knowledge.
Perspectivism is similar to subjectivism in that it claims that different conceptual schemes can result in a variety of moral judgements. However, it differs in that it does not consider the moral judgements as metaphysically "real" or to have equal validity.
Is or ought?
- Main Article: Is-ought problem
The is-ought problem is a meta-ethical philosophical concept articulated by David Hume. The states that prescriptive statements, also known as moral statements or "ought" statements, cannot be derived from purely descriptive ("is") statements. The implication of the concept is there is no way to justify morality based on only observational evidence. This type of argument is a form of non sequitur in that the conclusion does not follow from the premises.
Absolute grounding requires God?
- Main Article: Morality depends on religion
Craig claims that if God does not exist, there is no ground for absolute moral duties because there is no moral lawgiver. The implication being that a lawgiver could provide that ground. But this is false, lawgivers are still subjective beings and their presence doesn't guarantee moral objectivity. Even if a divine lawgiver required certain duties of us, all that would be necessarily true is that it required certain duties of us. It would not follow that the certain duties were therefore absolutely good or objectively grounded (i.e. Is-ought argument against divine obedience).
Craig thinks he can achieve absolute grounding by making use of Anslem's notion of a "greatest conceivable being.' According to Anslem's ontological argument: one can understand what's meant by 'a greatest conceivable being' such a being can exist at least in thought, but if it existed only in thought one can think of a greater being existing in thought and reality. Therefore, Anslem insists, if one claims to be able to conceive of the greatest being without ascribing to its real existence, one is contradicting oneself, and states the "greatest conceivable being" is one whose NON-existence is inconceivable. Of the well known flaws in this argument, perhaps the most basic, is that even if person A has in her mind a concept of the greatest conceivable being, no logic requires her concept to correspond with reality. As Kant pointed out, "whatever and however much our concept of an object may contain, we must go outside the concept of we're to attribute the object with existence." No ontological argument has establishes that there must be a god, that this god must have an essential nature, or that essential nature must be good. This leaves Craig's claim to absolute grounding no more than the unsupported assertion of a god and qualities Craig wants it to have to make his moral case.
We value generosity, compassion and fairness because we experience and appreciate their positive effects. When these are proclaimed "divine qualities", this isn't because anyone has observed these qualities from a god, no god has been established to exist, let alone one whose nature we can study. All what is happening is the qualities already judged independently to have value are being ascribed to an entity declared to exist and be good by definition. If we want to imagine an "idealized being" as a way of developing some basic principles of conduct, the most appropriate model we can relate to is something with human biology.
Rooting morality into a being "beyond our comprehension" only pushes morality beyond our comprehension. It is even worse when what we choose as a model is a god of ancient scripture depicting moral principles we hold being most basic (such as Ez. 9:5-6, God commands "slay the little children without pity.") When we tell ourselves there is an all-powerful entity that can do this, and still be "morally perfect," we create the very conditions that far from leading us to moral truths guarantee a moral confusion. Even if a god created our universe, nothing about the act or power of grand creation requires moral perfection. And even if the universe was created by a god somehow 'intrinsically good' no logic would require the being still to exist. Imagine if such a god existed yesterday but destroyed itself today, would torture suddenly stop being a moral issue? If so, then this god can't have embodied values of enduring relevance. Severing any connection with any absolute moral values. If not, we admitting that this god does not need to exist, destroying this moral argument's conclusion for the existence of god. There would be equally overwhelming problems with claiming that "moral values and duties are transcendental in nature, and therefore require a supernatural creator." As soon as we require things to be viewed supernaturally with "goodness" "badness" or "oughtness," as soon as we allow the supernatural feature in any of our explanations, the idea of a single supreme deity becomes just one of countless unknowable untestable concepts, all with their unhooked justifications.
In this case of transcendental values and duties could just as easily be the creation of a group of supernatural experimenters, arbitrarily making things "good" and "bad" as to study the effect on animal behavior. If moral values and duties had to have been created supernaturally, this alone would count against their validity as absolute. For that matter, any argument for the existence of god (even if they were valid), wouldn't provide a logical pathway to a god of any particular religion or scripture.
Other ways of classifying moral systems
Theistic morality is based on the assumption that there is a god who has absolute understanding of right and wrong, and orders people to obey rules as a condition for goodness, see Christian morality for an example. God's commands are sometimes considered sufficient to make absolute morality true.
Secular morality is a complex subject and is discussed in a separate article.
Contrasting morality with ethics
Morality and ethics both address human action, there is a difference in emphasis between them. Morals emphasise personal conduct, beliefs and customs. Ethics are generally more abstract concepts which apply to groups of people or strangers.