"Why be 'taught' something that is NOT binding?" That's actually and excellent question, Elsie.
First, you've got to make a distinction between Magisterial and non-Magisterial teaching; second, within the Magisterial teachings, a distinction between different levels of authority .
Let me try an example (centered around "water") to illustrate this.
Consider these statements:
- Psalm 146:5-7
"Blessed the one whose help is the God of Jacob,
whose hope is in the Lord, his God,
The maker of heaven and earth, the seas and all that is in them,
Who keeps faith forever,
secures justice for the oppressed,
who gives bread to the hungry"
- God made and owns all the water on the planet. He created food and drink for the good of all His creatures. (Ibid.) (Psalm 145:16 - You open Your hand and satisfy the desire of every living thing.)
- When the Son of Man comes in His glory, He will judge us on criteria such as "When I was thirsty, you gave Me to drink: for whatever you do to the least of My brethren, you do unto Me." (Matthew 25:31-46)
- It is murder to knowingly or negligently deny someone nutrition/hydration in such a way that it causes or hastens their death.
- It would be gravely morally wrong to knowingly or negligently expose people to pathogens or poisons in their drinking water.
- To protect drinking water from pathogens, water suppliers often add a disinfectant such as chlorine. However, chlorine itself produces byproducts which are poisons and may pose health risks.
- Chlorine can also be weaponized: concentrated chlorine can be a WMD in carrying out chemical gas warfare or an act of terrorism.
- A major moral responsibility for water suppliers is to provide protection from pathogens while simultaneously minimizing health risks from hazardous byproducts. Safe drinking water must be provided in amounts which are adequate for basic human needs (at least, preventing death from dehydration).
Chlorine shipments should be safeguarded and kept out of the hands of terrorists.
- Market forces cannot be the sole determinant in fundamental matters such as water purity and water supply; the common good takes precedence over private profit, short-term public budgetary savings, political manipulation or military advantage.
- Access to critically needed water can involve international relations. International accords should ensure that highest-bidder market processes or international power plays do not leave whole populations of helpless people dying of thirst.
- There should be international regulation of international shipments of chlorine so that it does not become weaponized in the hands of terrorists or rogue states.
As you can see, these quotes all deal with water and faith and morals, and judgment between right and wrong. However all of these statements do not bear the same authority.
My own quick assessment would be that
- #1 is inerrant because it is Scriptural Revelation.
- #2 and #3 are Doctrines directly and necessarily derived from inerrant Revelation.
- #4 is Moral Law based on Divine and Natural Law, as authoritatively expounded by the Catholic Church.
Therefore, #1 - #4 are always morally binding.
- #5 is Moral Law, but it is contingent and partially a prudential judgment, as you can see when you look at #6 and #7.
- #6 and #7 are scientific statements of fact. As such, they are not, in themselves, part of Magisterial teaching. But they have an important impact on #5, as well as on #8,#9,#10 and #11.
- #8 and #9 are part of the Social Teaching of the Church, and are necessarily derived from both Divine and Natural Law.
Scripture gives us critically important examples of just behavior:
(Psalm 36:7) "Your justice is like the highest mountains; your judgments, like the mighty deep; human being and beast you sustain, Lord." -- the Lord's justice sustains life;
(Proverbs 31:9) "Open your mouth, judge justly, defend the needy and the poor!" --- public authorities' first duty is to sustain life, as a matter of justice, even for people who at the time can't pay for it, i.e. the needy and the poor;
- #10 and #11 are prudential judgments, i.e. they fall under the category of international diplomacy, trade, and public policy. They are not Magisterial per se. However, they deserve careful consideration as to whether they are the best ways to carry out the requirements of justice.