I have the same burden of proof that any other theory of morality has. It has to be logically sound. Logically, if conscience is our only moral authority, then we have to consider its guidance infallible and universal.
This argument is already logically unsound. There is no reason why it has to be universal, yet you take that as a given.
Humans differ in many things: strength, eyesight, ability to see colours, intelligence, emotional intelligence, spatial awareness, etc.
The 2nd logical error is to assume it is infallible, at least in the sense of producing a
humanistic kind of ethics (I assume you believe this, it wasn't clear from your post, if not please correct me).
In addition we are subject to emotions and biases, so why assume infallibility when we are very flawed creatures.
Further, moral indignation drives many atrocities. Many terrorists, for example, believe they are fighting a very ethical cause.
There is a quote (can't remember from who) which goes roughly: "Murder done for evil reasons is the anomaly, the majority of killings in human history have been done in pursuit of a [subjectively] noble cause".
I'll open with the axiom that all knowledge begins with a sensed experience. In other words, we have to first notice an effect, as in "cause-and-effect," before we can learn anything. The scientific method begins with an observation.
So, since our long-ago ancestors couldn't see, taste, hear or smell the difference between moral right and wrong, they must have felt it. So, our species learned about morality from the moral intuitions we refer to as conscience.
Therefore, the conscious reasoning faculty of our brain would know absolutely nothing about making moral choices if it hadn't learned from the moral intuitions that emerged from the unconscious.
If conscience derives from sensory experience, and sensory experience varies greatly from person to person, why should we assume universality?
We are pattern seeking creatures, although we perceive patterns in a very flawed manner. We start with a base sense of empathy, fairness, etc., although one which varies from person to person, and then this interacts with our sensory experience to create our own sense of morality.
According to Yale psychologist Paul Bloom, humans are born with a hard-wired morality. A deep sense of good and evil is bred in the bone. His research shows that babies and toddlers can judge the goodness and badness of others' actions; they want to reward the good and punish the bad; they act to help those in distress; they feel guilt, shame, pride, and righteous anger."
This is another scientific perspective that rejects your overall contention. Bloom accepts differences between individuals:
What is the strongest proof that morality has a genetic component, that two people may have differing moral views because of their genes?
There have been the usual sorts of behavioral genetics studies—adopted children, twins separated at birth, that sort of thing—
that find evidence for heritability in capacities such as empathy, which is plainly related to morality.
The Moral Life of Babies
Is there any research that supports you actual position, as the ones you have quoted support the opposite: moral diversity rather than universalism.
He also notes this on the concept of 'infallibility' and resining:
Are there ways that the moral emotions you mentioned — like “righteous anger” — lead to behavior that we would call “immoral”?
Absolutely. Our emotions have evolved for simpler times. They are not well calibrated for the modern world, where we are surrounded by countless strangers and have access to cars, guns, and the Internet. It makes sense to be outraged when you are deceived by a friend or when someone you love is wronged. This can be a moral response. But it is irrational—and often immoral—when the same anger is acted upon towards someone who cuts you off on the highway. Worse, righteous anger can provoke international confrontations that can lead to the death of millions. Anger is one thing when you are armed with your fists and a stick; quite another when you have an army and nuclear weapons.
It’s not just anger, though. All of the moral emotions can have disastrous effects. As I argue
in a recent New Yorker article, I think this is true even for empathy—the capacity to put yourself in someone else’s shoes, to feel their pleasure and their pain. When it comes to personal relationships, empathy can be a good thing—I wouldn’t want a parent, a child, or a spouse who lacked empathy. But, just as with anger, empathy doesn’t scale. It is because of our empathetic responses that we care more about a little girl stuck in a well than about billions being affected in the future by climate change. The girl elicits empathy; statistical future harms do not. To the extent that we can recognize, and act upon, serious threats that don’t have identifiable victims, we are relying on rational deliberation, not gut responses.
Conscience is cross-cultural but does not seem to be because of cultural biases. If a man kills another in a clear case of self-defense, a jury would find the killing justifiable in every country of the world. But if a woman kills her husband in self-defense, she would not get a fair trial in many cultures. In time, the conscience-driven movement to treat women equally will sweep across the world just as the conscience-driven movement to abolish legal slavery swept across the world. When all cultural biases are eliminated, it will be obvious that conscience is cross-cultural.
You also make another baseless claim: that cultural biases can be eliminated. Culture is an indelible aspect of human socialisation and, outside of wishful thinking based on an ideology invoking a progressive teleology, there is no reason to assume a universal culture will appear.
Our moral intuitions are probably are aligned with the survival of our species.
Our moral intuitions are probably related to our need to form groups, we didn't evolve to think at abstract constructs like Humanity.
It is almost undeniable that our cognition is based around in/out group divisions, and we are biased towards our in group and against the out group.
It can become easy to justify cruelty towards out groups, as we see from science, history and in the behaviour of our closest relatives, chimps.
A soldier who believes he is fighting in a good cause will kill his enemy; but if he is ordered to kill civilians living in enemy territory, his moral intuition (conscience) will immediately protest. The act will feel wrong. If he ignores this moral guidance and obeys the immoral order, his moral intuition will have him feel guilt throughout his lifetime, whenever he remembers his offense.
History would say otherwise. Innocence is a very malleable concept, it's very easy to see civilians as 'fair game'.
Once the questions of fact are answered, moral judgments are the province of conscience; we should feel the answer:
-- Does this act feel morally wrong?
-- What treatment of the offender would be fair?
Most ethical decisions exist in morally grey areas. Frequently we face moral dilemmas where one group benefits and another loses out. There is often no offender and the 'best' course of action will depend on numerous axioms which guide the moral judgement.
So, please explain: How did the products of our reasoning minds improve on the quality of our moral judgments? How did the Student surpass the Master? Didn't the products of our reasoning minds simply confuse us?
As you said, conscience comes from sensory experience. We are exposed to events and other people's ideas. Our mind is a complete system, existing as part of numerous dynamic feedback loops. Even if everything was intuition, our intuition can take into account other people's reasoning that we have been exposed to.
Human nature is also complex with violence and kindness, vindictiveness and empathy all parts of our evolved cognition. We didn't come down from the trees as warm, fuzzy, universal Humanists. We are tribal and competitive, like our primate relatives
Modern moralities evolved over time due to cultural, social and technological changes as part of a dynamic feedback system. As part of this, we have mitigated some of the darker aspects of human nature, although that doesn't mean they have disappeared.
Your argument is pretty much a retelling of the Biblical Fall couched in secular language. We started off perfect until we became corrupted by events.
Overall, some of the reasons your argument is logically unsound:
1) Your claim of universalism is completely unsupported. Also if morality is partially genetic, and we are genetically diverse, why assume morality is magically exempt from this?
2) Infallibility ignores our very human flaws, even our vision necessarily incorporates bias and guesswork, yet morality is again magically exempt.
3) Even assuming infallibility, there is no reason to assume it reflects a modern Humanistic ideology focused on an abstract 'greater good of Humanity'.
4) Culture grows out of collective experience, and experience is diverse hence cultures are diverse. There is no reason to assume culture will disappear of become universalised.
5) Most of morality relates to grey areas, yet you have not discussed how a universal, infallible morality works in such areas.
6) In/out groups are an evolved, and indelible aspect of our cognition, yet you ignore this.
7) Reasoned arguments are part of our sensory experience and thus feedback into intuition.
