Assume morality is objective.
Binary morality is a coherent and logically consistent framework for understanding objective right and wrong. There is nothing to support its implausibility - our finding it too bare is our problem. It is not casting doubt on it.
By assigning every action or state of affairs a single, uniquely correct moral value—permissible (1) or impermissible (0)—it avoids ambiguity, relativism, and subjective interpretation.
Unlike graded moral systems that require continuous metrics of goodness or badness, binary morality aligns with the logical principle of non-contradiction: an action cannot be simultaneously morally required and forbidden. It also simplifies ethical reasoning, focusing attention on what must or must not be done rather than attempting to quantify moral “degrees.” Furthermore, there is no evidence against it: all observed moral intuitions and judgments could be consistent with a binary framework, making it a defensible candidate for objective morality.
Binary morality doesn’t directly adjudicate metaphysical beliefs. Christianity says God makes only good so evil is a mere lack of good. It says that human evil lacks good but also takes good and distorts it. This denies that evil is a presence or a substance or an intelligence in its own right.
The Manichaean view is that evil is indeed a presence or a substance or an intelligence in its own right.
Christianity commands you accept the lack teaching - it is a sin not to.
Manicheans command you to accept the substance teaching - it is a sin not to.
Binary morality does not care what you do. It will look at actions such as stealing. It effectively tells you to ignore those faiths.
For it, avoiding evil matters more than what you think evil is.
SYLLOGISM
Major Premise: A morally perfect God would command humans only regarding matters that are morally relevant.
Minor Premise: The metaphysical nature of evil (e.g., whether it is a lack or a substance) is morally relevant, because it affects whether God is culpable for creating evil.
Observation: Binary morality evaluates actions as permissible or impermissible but says nothing about the metaphysical nature of evil.
Conclusion: Therefore, binary morality does not fully capture the moral perspective of a perfectly good God.
The syllogism demonstrates that God cannot be the ultimate ground of morality at all.
Binary morality evaluates actions as permissible or impermissible but is indifferent to the metaphysical nature of evil, while a morally perfect God would need to care about the nature of evil to possess moral authority, since creating evil or allowing it is morally significant. This creates a tension: if morality is grounded in God, it would need to reflect his concern about evil’s nature, yet binary morality ignores this entirely. The contradiction shows that God’s moral perspective and an abstract binary moral system cannot be perfectly aligned, undermining the claim that God alone grounds objective morality.
But what if your morality is not binary?
Binary remains the minimum and the core. Even if morality is not strictly binary, binary morality represents the minimal core framework from which any broader system must build.
APPENDIX:
Doctrines such as sin deserving eternal exclusion from happiness or the existence of an everlasting Hell are without doubt fanatical. Binary morality would say no to those who command belief in those things. The reason is that as long as you are minimally decent, it classes you as good. Alleged sins such as homosexuality or masturbation or blasphemy would be tacitly ignored. Ignoring big moral commands is tacitly denying their value.