The first hazard comes from the origin of morality.
Some people believe that every ethical system in every society is the product of the collective effort, i.e., every member in this society has been contributing to the formation and development of a morality. These people believe that every person in this society will willingly accept this morality because it is the voluntary invention of every person. Some conservatives believe in this so seriously that they have a great antipathy toward any deliberate reconstruction of morality and label it as "the road to serfdom".
But the fact is that so many kinds of moralities (especially traditional moralities) are not collective efforts. These moralities are invented by one man or a small group of men, and later carried out by rulers who themselves appreciate these kinds of moralities very much. As to the most ordinary people, they even don't know this new morality in the beginning, after the ruler's implementation of it, the people can do nothing but unwillingly accept these new moralities because if they do not they will be cracked down by rulers. For example, Confucianism is one of these kinds of moralities. Confucianism was invented in 6th to 5th century BCE by mere one man, when there are many other competitive ethical systems invented by other thinkers and only a small group of people believed in Confucianism. But at the time of circa 150 BCE, a Chinese emperor appreciated Confucianism very much and he thought that if all the people appreciated it the world would be a paradise on earth, so he implemented his blueprint forcibly. This has influenced the destinies of nearly all Eastern Asians afterwards. Christian morality and Islamic morality are also implemented through this process. In the spreading of the two religions, the rulers' atrocities against infidels who didn't mean to accept them are well documented.
After people accept a new ethical system for a long time, implementation of this morality will become a culturalized and everyone in this society usually automatically conforms to this morality without a ruler's punishment. But this automatic conformity does not mean that people have interests in it. They automatically conform to it because when they see other people conforms to this morality automatically they think other people have loved it and if they do not they will be boycotted by other people. No one wants to be boycotted, so everyone has to conform to a morality even though he/she feels so dissatisfied with it. If everyone thinks that "immorality" will be boycotted by others then no one have the courage to challenge a morality.
So, a morality can be the enemy of the most majority of people because only a small percentage of people like it while all other people who don't like it have to obey it.
The second hazard comes from the role of morality.
A morality is a system of standards which judges what conduct is "right" and what is "wrong". But morality itself is immune from this kind of judgment. A morality thus usually becomes a forever-correct thing. So we see that a morality can condemn a man who wears pants as "immoral" but no one dares condemn this moral code as "immoral". Morality loses its ability to correct. This is a dangerous fact. In history, most man-made calamities are due to this immunity of morality. In the Dark Ages, the Inquisitions burning witches and infidels is "moral" because forever-correct Bible (more properly, the forever-correct morality induced from Bible by a small group of theologists) said so. In Islamic society, a woman not wearing hijab is "immoral" because the forever-correct morality induced from Koran and Hadith said so. But no one dare question these cruel "forever-correct" moralities.
In modern society, various nationalists, multiculturalists, patriotists, cultural conservatives, "international democracy" preachers and fundamentalists preach various moralities which label various unbelievers of their theories as "reactionaries", "impudent beasts", but their theories and moralities are hard to criticized. Because as long as you criticize them, they will say that you have violated the noble morality first and agitate people to crusade against you. Criticizing morality must violating that morality first. People usually think if they violate morality they will be boycotted by other people. So you can see how hard for people to criticize a morality. But without criticism no ideology can correct its own faults. The faults of morality will last forever.
Morality judges whether a conduct or idea is right or wrong, but morality itself cannot be judged in this way because it is the basis of this judgment. This is the second hazard of morality.
The third hazard of morality lies in its function.
A morality is a thing that needs our observance. Observance means the act of following a law, custom, command, or rule. A morality is a law, custom, command, or rule. They all share one common feature: the restriction on the exertion of free will or human ability ---- even if you are able to do something you should not do it anyway. For example, "Do not steal" is a morality, but of course you are able to violate it. But in practice you should not steal anyway. That's the restriction on your ability. Some moralities even order people (especially women) not to think about sexuality, that's the restriction on one's free will.
We usually hear people say that, "things on earth follow the rule of gravity". But this "follow" is drastically different from that "follow". Here the "follow" does not mean following a rule that restricts the exertion of free will or ability. In this situation things can do nothing but follow that rule. They have no choice but to follow the rule. This "rule" is of course not the "rule" in the sense of morality. This "rule" (rule (I)) is a default course of events, and that "rule " (rule (II)) is the restriction on the use of human ability or free will. The difference is fatal. Only rule (II) can be a morality, rule (I) cannot be a morality.
But this difference is usually overlooked and even obliterated. In our society, rule (II) is usually mistakenly deduced from rule (I), or more terribly, rule (II) is usually regarded as the same thing as rule (I).
Rule (I) is usually seen as an absolute course of events, which means no one is able to alter it in any situation. But this viewpoint is wrong. Following rule (I) is not unconditional. Only when all its relative conditions meet, then a thing following the rule becomes absolute. For example, only when the value of gravity is larger than the value of an upward force, things will fall. In ordinary situation, these two conditions are arranged in this way, so we usually see things falling. This is the default course of events. But a balloon does not fall but rises, because its buoyancy is larger than its weight. This means, although if all relative conditions meet things will absolutely follow a rule (I), yet as long as one condition does not fulfill, things will not follow that rule (I). Rule (I) is absolute but conditional. Things need not absolutely act in their default ways.
But according to our experience, rule (II) (which morality belongs to) is usually unconditional. It is the restriction on the use of human ability. That means even if you have the ability to violate it, you cannot act by your very ability. What does "violation" mean? It means the act of not following a law, custom, command, or rule; or, the act of invalidating a law, custom, command, or rule.
Let's reconsider rule (I). The violation of rule (I) means not following it or invalidating it. But a natural course of events is prescribed by inevitable nature. How can it be "violated" (therefore evaded)? This point is crucial and must be noticed. When people say that you violate a rule (I), this does not mean that you have supernatural ability. It just means that you are altering the arrangement of conditions which together can render fulfillment of a rule (I). And this alterability is also in accordance with nature, not violating it. For example, many people believe that human cloning is violating the nature because humans are sexually reproductive animals. But sexual reproduction is just a default course of events. It has its own premises and conditions. If one premise or condition has been altered according to biological or physiological laws, sexual reproduction can be replaced by other kinds of reproduction even though sexual reproduction is seen as "default".
If these two kinds of "rules" are confused, the consequence is terrible. If rule (I) is seen as the same thing as rule (II), then even if you are able to alter rule (I) ( = rule (II)) you cannot use your very ability because that will be immoral.
In history, morality is the primary obstacle to scientific progress and human happiness. Since the maintenance of defaults is acknowledged as a morality. Till now morality goes on to hinder our progress and happiness. The rights of homosexuals are denied because their sexual functions are not seen as "defaults". New reproductive techniques are opposed by many people because it has the ability to change the "default" way of reproduction. Nature worshipers are the fanatic believers of this morality. They think all kinds of exploitation of nature are evil because they violate the natural rules therefore immoral. They even groundlessly believe that "She" (the nature) will punish humanity for their "atrocities". I usually think, when people lived in several hundred years ago believed that "Things Must Fall" were a morality, balloons, airships and airplanes would be all "immoral" and therefore never come into being.
When morality becomes a maintainer of the course of events that can be safely altered, it must become the obstacle to human progress and happiness. That's the third hazard of morality.
The three hazards of morality can and do impair all the people in the world. So people must keep cautious of these negative effects and find a way to minimize them.