This is probably the ten billionth time I'm quoting this, but 'What Heaven has conferred is called The Nature; an accordance with this nature is called The Path of duty' (Doctrine of the Mean). Mother Nature has given humans the gift of the Nature. Humans are by nature benevolent; Mother Nature has endowed upon us the abilities of benevolence, righteousness, propriety and wisdom; to adhere to these principles at all times is to follow the Path, and to follow the Path is what morality is all about.
There must be objective truth. Claiming that objective truth doesn't exist is contradicting itself, since it's a claim that is itself defended as objectively true. It follows that moral propositions must have an objective value as true or untrue. Whether ethical naturalism is true or not is a slightly different question. All my argument says is that there MUST be an objective answer, so it's not subject to the is-ought fallacy.
Humans developed morality through group dynamics and the reliance on groups for survival, thus our morality evolved around group dynamics and group nurture. Thus we developed nurturing habits and a strong value for other members of our group, so we treated the other members with due respect, because survival of the group is for our own survival. As our brains developed, we evolved culture, thus the group as a whole developed a culture of it's own individuality. Each culture developed similar group caring/nurturing morals (do not kill others in your group and Treat Others In Your Group As You Would Have Them Treat Yourself, etc..) but other morals differed as groups survived in different environments. So internal group Morality evolved similarly, but external, Environmental and Towards Foreign Group Morality often differed markedly.
I take this question to mean "Does objective morality exist or is moral nihilism more likely true?"
Where would we objectively prove morality? Morality is "what ought to be". Let's say there was an objective morality but it not only never manifested but nobody ever came to believe in it. How would the world be any different from if it did manifest or if at least significant numbers of people believed in it? Not at all. Then objective morality doesn't exist.
Generally people tend to form opinions about what ought to be and what ought not to be. And we've been doing that since forever. The mainstream morality in a given society at a given time depends on the endless tug-of-war between different views. Some views are clear losers some of which I hope will long remain losers such as the pro-slavery position.
We had ages of slavery, and other forms of injustice to women, people who can distinguished on the basis of something or the other. If what we define as "morality" existed, then these wouldn't have existed to the extent in size and age as they did. Morality is just a way for the conscience to ensure that what is being done is justified and will change according to time. Thus only moral nihilism is right and feels correct
This is a simple question. Each person is given a conscience by God, which tells them what is right, and what is God. Ask a child if taking a toy is wrong they will agree, or if they lie they look guilty. The conscience can be seared, or silenced, but it does exist. Everyone has the chance to discern right from wrong. Moral nihilism is a dangerous belief, for if each can decide what is right for himself, who is to say someone is wrong when the steal, or rape, or kill?