Let’s look at this in terms of brain evolution. For the reptile, good and bad are certainly Manichean. What you can eat is good and what can eat you is bad. Pleasantly simple. As long as you get it right. Of course, as Rappaport reminds us, there are two kinds of survival: that of the individual and that of the group. Lizards don’t worry about it.
A mammal group
Then comes the mammal brain when the group is important because mammals must invest in birthing families, which are the core of bands, and then tribes with their bonded center of genetic connection and the looser surrounding relationships based on affinity. By the time these bands and tribes exceed a hundred members, there begin to be difficulties between individuals, between groups, and between the individual and the group. Two forces evolved to regulate these oppositions: one is the pack structure with an alpha, sometimes two (a male who fights, a female who keeps the pack or herd knowledge and teaches the cubs or calves). And then the one for humans that came with language: written rules like the Ten Commandments or the Code of Hammurabi.
A stele recording the Code of Hammarabi
Human groups who could write developed bookkeeping systems, stories, and courts of both justice and status. Sometimes they illustrated principles in ceremonies, drama, and artistic depictions. The laws remained rules rather than principles until the evolution of the pre-frontal cortex, which was able to weigh conflicts in order to reconcile them. With the advent of spindle cells, some of these principles reflected awareness of compassion. This is where Jesus, Buddha and Mohammed enter history. Confucius, not so much.
No animal, no mammal except primates, has morality or ethics that employs a pre-frontal cortex because the only animals with that part of the brain are elephants, whales, dolphins, and humans. The empathy of dolphins is sonar-powered: they don’t have to read your face because they can hear your guts, but even they can be governed more by instinct than by “rules.” Except that all humans and most mammals can be brain-shaped by operant conditioning: that is, the powerful “rule” of doing what is rewarded and not doing what is punished, a duality without nuance. Domesticated animals (and humans) are conditioned animals. Ferals have slipped the bonds of punishment and reward, sometimes because the two are conflated or reversed: what was once punishment has become rewarding, or vice versa. Or simply lost their meaning.
Generally, the term “morality” applies to ordinary daily behavior and “ethics” is more abstractly principled, requiring reflection. Morality can be forced by external monitors but ethics are more often thought and felt by the acting individual. Neither has anything to do with spirituality, which is a whole-body response to the universe, entirely amoral, beyond ethics. Morality is mammalian, ethics are human, and spirituality transcends humanness to include all of existence. That's just tentative, but I like it.
Yet mainstream institutional religion in America concerns itself mostly with morality (esp. on the conservative side) while ethical behavior is confined to more thoughtful circles -- academic, legal. Much of this may be because there are so many unreconciled cultures and because the world is so changed by technology that many moral assumptions must be re-thought. Now that we know skin color means nothing, the morality of miscegenation is obsolete. Now that we know so much about conception, gestation and birth, many choices are forced when once we were only asked to accommodate whatever happened. Something similar affects our behavior concerning death. We have increased the stress and exploitation of our environment to the point of altering it into something that kills us. All these are moral and ethical issues requiring many adjustments.
But spirituality infuses our being with something beyond that. It is even beyond the commonly assumed value of compassion. Because the pre-frontal cortex of primates contains spindle cells that allow empathy -- shared experience, knowledge of what someone else is feeling -- many people want that information included in thinking about decisions, even awareness of the “enemy’s” likeness to ourselves instead of defining them as something “bad”, i.e. to be eaten.
This lioness killed a mother antelope and then tried to adopt the baby.
It is the mammalian need to nurture that can overwhelm everything else so that maybe the lamb doesn’t lie down with the lion, but we witness a lioness who tries to raise an antelope in spite of the obvious difficulties. It is a “mommie” impulse (mommie from mammal) that wants everything safe, warm, fed and clean. Mammals like cuddling and nurturing. That helps individuals survive. It may not help the group get through risky, cold, dirty and violent circumstances whether from natural disasters or unreconciled warfare. Mommie stuff means vulnerability. We take children away from abusive parents and then place them with abusive foster parents.
I say “mommie” where others say “nannie” because nannies, at least in the English culture, are rule-enforcers, dedicated to the rules of the group (censoring) and the shaping of the young into useful adults (conditioning). A mommie cares about nothing except her own child and its welfare. A mommie will lie, cheat, steal, and kill to defend her own cub. But it is based on ownership, that the cub is an extension of her and her pride. If it defies her, she may kill it herself, not recognizing that it is a separate being.
I have been careful never to have children because I could not stand either the loss of them nor the compromises necessary to provide for them. I am selfish. The dark side of mommies is the huge cost to the mother from the point of conception to the witnessing of death. But “momism” is still a potent force in the culture and still connected to sacrificing young men, as in war.
Rather than being a phenomenon of part of the brain, spirituality engages the whole body and all its experience of the past and ability to envision the future. It is mostly unconscious, because human consciousness in the sense of identity and purpose is a small sub-part. Spirituality is participation in the totality of the universe, not the preservation of the identity of one person or their body, but rather the total interaction of patterns that is Being. Awareness of it is only in glimpses and that’s a good thing because it is so powerful and overwhelming. It’s not very helpful in terms of making decisions.
Spirituality can be confused with madness. It worries people. It might trigger attempts to control or even eliminate a person who seems to see beyond the culture horizon. Sometimes a culture will set a highly spiritual person apart, even found an institution in his or her name, which is a pity because institutions destroy spirituality. Lifting spirituality up as a founding impulse only puts it in a box, even a coffin.