Such moral precepts can be taught in schools with strong religious or moral uniformity. But would they provoke many a parent’s fears of indoctrination? (See Education without Indoctrination: is it possible?) And why, do most people in today’s United States of America -- though not, one suspects, Socrates' Athens -- reject the idea that “Love Thy Neighbor” might rationalize pederasty?
When are Moral Rules absolutely binding? Kant’s advice not to lie, even to a murderer seeking his victim, makes one wonder. Clearly, there is a lot of slippage as to what teaching morals -- or “values,” to use more au courant terminology -- amounts to. “Teaching” is a highly ambiguous term: its results, i.e. values taught, can vary greatly. To be able to repeat a rule does not indicate, in itself, that one would follow it when not supervised. (See What is Worth Knowing About Values)
Just preaching Do’s and Don’t’s doesn’t go very far to inculcating them -- as “Do as I say, …” jokes suggest. Mere preaching does not teach how to use moral precepts accurately in real situations. (See What is it to know how to use a principle?)
Moral Priorities in Context. One approach to applying rules -- not only moral rules -- coherently and consistently in varying situations is to prioritize them according the degree of “sacredness” you accord them. Thus, if protecting innocent human life is of higher priority than telling the truth, you will lie to the murderer seeking his victim. (See Prioritizing Principles)
Even “sacred values,” i.e. those values you most strongly resist changing, can conflict. To invoke two Biblical commandments: Does informing about your parents’ criminal behavior honor them? Suppose they are political opponents of a dictator?
Consider also the conflict between virtues: telling the truth, and being kind. Your child draws a picture of you and asks, “Do you like this?” You are very likely to say, “Yes,” despite the picture’s being grotesquely different from your reflection in a mirror. Absolute morality tends to generate hypocrisy, or force choices between competing evils or goods. (See Teaching Values: early lessons in hypocrisy.)
Whose Evil? Whose Virtue? We live in a pluralistic society comprising many different cultural groups. Civil law binds us to behavior that does not infringe on many of the cultural practices of different groups. We even have public rituals of acceptance in this 21st Century for groups who were -- not so very long ago -- publicly despised and deprived of legal rights, e.g. Blacks, Irish, Chinese, females, disabled, etc. However, despised differences persist today although their public expression is either legally forbidden or “out of style.” (But public schools still have to deal with such animosities. See “Sacred Values” in US Public Schools: pretending there is no conflict.)
Why Not Teach Situation Ethics? If there is one persistent educational side-show, it is the business of educating various groups in ethics. Captive audiences, scholastic or corporate, learn to talk a good line to meet both federal and local standards of “civility.” Offenses, even in the use of recently tabooed vocabulary, merit headlines in proportion to the celebrity of the offender.
The trouble with situation ethics is that it promotes, indeed, requires individual freedom of choice. Situation ethics is ultimately based on what each individual considers fundamental, be those values idiosyncratic or social. This opens up the possibly of rejection of the values which other autocrats would have us commit to.
So, blather and obfuscation, presented in many venues, often with abundant libation (school kids, excepted), in order to loosen tongue and muddle thought, lard expatiation on ethics or morals.
(See Teaching Values: a waste of time?)
But Sacred Values Universalized Restrict Individual Freedoms! Morality, “sacred value.” presumes a Leviathan, whether individual, e.g. a secular or religious autocrat or institution, that demands constancy of allegiance. Otherwise, as Thomas Hobbes puts it, we are in a condition of war, each of us against the other. (See The Quest for Constancy )
However, we face a conflicting demand: Individual freedom is no virtue lacking morals, i.e. commitment to common sacred values.
What is liberty without … virtue? …It is the greatest of all evils… -- Edmund Burke
Adam Smith would have agreed with him.