I often see or participate in conversations where two or more morally decent individuals,  acting in good faith,  make different decisions or hold different opinions when faced with moral/ethical choices. In his book The Righteous Mind: Why Good People Are Divided By Politics And Religions, Jonathan Haidt offers a useful framework for understanding this. Cogitive psychologists have names this Moral Foundations Theory.

Haidt and colleagues posit that:

    •    People use a defined set of qualities to evaluate the moral or ethical status of an idea or behavior.
    •    This set of qualities is relatively consistent across cultures.
    •    That different moral or ethical judgements are less often related to how one ranks something on a particular scale than how important particular scales are to an individual.

I find this non-controversial metaphor useful to illustrate the concept.

Imagine asking a handful of friends and acquaintances to pick their favorite apple variety. One friend might name the Gala because they use apples primarily as a snack and like it's crispness, sweetness, and juiciness. Another might opt for the Golden Delicious because they like making pies that are not too tart. Someone might select the Granny Smith because they like making pies that are quite tart. Those who like to make and store applesauce might prefer Honeycrisp or Fuji, or perhaps Pink Lady if they like tart applesauce. Despite picking different 'favorite' apple varieties, this group of friends would likely agree on the descriptions of the apple varieties in terms of juiciness, crispness, tartness, sweetness, or the like - but then disagree on which characteristic is most important (salient in cognitive psychology jargon) to them.

Haidt uses a similar framework for describing one important aspect of how people with similar core values often come to very different and seemingly irreconcilable conclusions when faced with a moral or ethical choice. The core categories his research has identified across cultures, genders, and languages are:

    •    Care/harm
    •    Fairness/cheating
    •    Loyalty/betrayal
    •    Authority/subversion
    •    Sanctity (purity)/degradation
    •    Liberty (autonomy)/oppression

(Note: others have identified and argued for additional moral qualities, including but not limited to ownership/theft, honesty/deception, efficiency/waste.)

How does this explain different stances about something like vaccine mandates? Two people might agree that (1) vaccines are effective and support public health despite a small number of potential harms; and (2) that liberty (personal autonomy) is an essential part of a free society. The person who sees care for society as their most important core value will likely favor vaccine mandates, while the person who sees personal autonomy as their most important core value will likely oppose vaccine mandates. Because humans are inherently motivated reasoners, both will find and use arguments and information that support their stance and struggle to recognize that the difference is not inherent in the vaccine but is inherent in the difference in their core values. It is not that the person who supports mandates does not feel autonomy is important or that the person who opposes mandates does not feel societal health is important. They simply differ in their personal prioritization of autonomy and care as core values, just as they might differ in their prioritization of crispness, color, sweetness, tartness as most important in an apple.