Is secular moral realism (Parfit, Scanlon) sufficient to establish objective morality without God?

Secular moral realism — as developed by Derek Parfit in "On What Matters" (2011-2017) and Thomas Scanlon in "What We Owe to Each Other" (1998) — represents the strongest contemporary attempt to establish objective morality without recourse to God. This attempt deserves careful analysis because it challenges the traditional claim that "no objective morality without God." The discussion here is not about God's existence, but about whether objective morality is logically possible without assuming his existence.

Inadequate Responses to Avoid

From some defenders of theism:

"Secular morality is just disguised personal opinion." This is a grave error. Parfit and Scanlon are first-rate philosophers in the Anglo-American academy, and their arguments are technical and complex. Dismissing them with sophistic slogans shows ignorance of contemporary debate.

"If God does not exist, everything is permitted." This is Dostoevsky's famous slogan, but it is not a philosophical argument. Secular moral realists provide a complex structure for establishing moral standards without God. Rejecting this structure requires analysis, not mere repetition of slogans.

From some secularists:

"Parfit and Scanlon have proven that morality does not need God." This is an overstatement. What they have provided is a coherent theoretical framework for secular morality, but this framework faces serious challenges. The philosophical debate remains open.

"Religious arguments for morality are circular." This is a simplistic accusation. Contemporary arguments from morality to God (in Adams, Evans, Zagzebski) are not "God says X therefore X is correct," but complex arguments about the best explanation for moral facts.

Why These Responses Are Inadequate

They share in simplifying a deep philosophical debate into slogans. The real question: Can secular moral realism provide a sufficient foundation for objective morality? The answer requires examining the internal structure of these theories.

Parfit's Realism: Irreducible Normative Facts

Parfit proposes that there are objective normative facts that are irreducible to natural facts. For example: "Torture for pleasure is wrong" is not merely an expression of feeling or social agreement, but an objective fact like "2+2=4".

The basic argument: When we think clearly about certain moral cases (torturing an innocent child for pleasure), we directly recognize that this is wrong. This recognition is not an inference from other premises, but a priori knowledge like our knowledge of mathematical facts.

Parfit distinguishes between three types of facts:
- Natural facts (water is H2O)
- Mathematical logical facts (2+2=4)
- Normative facts (torture for pleasure is wrong)

The third type, in his view, is objective and real like the first two, but irreducible to them. These facts "float free" in reality, needing no metaphysical foundation in God or nature.

Strength: Respects our strong moral intuition that some acts are objectively wrong, regardless of opinions or cultures.

Weakness: The "free floating" of normative facts appears metaphysically obscure. How do these facts exist? Where do they exist? What is their relationship to the natural world?

Scanlon's Contractualism: What Cannot Be Reasonably Rejected

Scanlon offers a different approach. Morality, in his view, is founded on the principle: An act is wrong if it is forbidden by principles that no one could reasonably reject, as the basis for a general and binding agreement.

The key here is "reasonably reject." This is not actual rejection (many people reject correct moral principles), but reasonable rejection from the perspective of someone seeking principles that everyone could accept.

Example: The principle "do not lie except to save life" can be defended because it protects everyone's interest in mutual trust, with a reasonable exception. The principle "lie whenever you want" cannot be defended because everyone would reasonably reject it — it destroys the possibility of trustworthy communication.

Strength: Provides a clear procedure for determining moral principles without recourse to external authority.

Weakness: Assumes that "reasonableness" is an objective neutral concept, while standards of reasonableness may differ between cultures and individuals. It may also result in disguised relativism.

The Theistic Critique: The Grounding Problem

Theistic philosophers (Robert Adams, William Craig, Linda Zagzebski) raise a fundamental critique: Even if we accept that there are objective moral facts, the question remains: What explains the existence of these facts?

According to Adams in "Finite and Infinite Goods" (1999): Moral facts need "grounding" in reality. Mathematics may "float free" because it is purely abstract, but morality concerns conscious beings and their actions. How do "floating" facts affect the world of consciousness and action?

The deeper critique: Even if we accept Parfit's realism, why should we care about these moral facts? If they are merely "floating" facts with no relation to our nature or purpose, what makes them binding for us?

God — as creator and source of good — provides a unified explanation: Moral facts are objective because they are rooted in God's nature, and binding because we are created in his image and for a moral purpose.

The Problem of Moral Obligation

Even if secular realism succeeds in establishing the objectivity of morality, the problem of obligation remains. Why should I do what is right, especially when it conflicts with my interest?

Scanlon answers: Because you want to live in relationships that can be justified to others. But what if I do not care about this? What if I am a "rational egoist"?

Theistic theory provides a stronger answer: Moral obligation is not merely "what should be done if you want X," but absolute commitment flowing from the nature of creation and humanity's ultimate purpose.

Contemporary Secular Responses

Sharon Street in "A Darwinian Dilemma" (2006) turns the critique around: If our moral beliefs are products of evolution for survival purposes, how can we trust that they connect to objective moral facts (whether natural or divine)? This affects theistic realism as well.

David Enoch in "Taking Morality Seriously" (2011) defends "robust realism" and argues that rejecting moral realism has a practical cost that cannot be accepted: We live as if morality is objective, and theory that denies this fails to explain our experience.

Critical Assessment

Secular moral realism provides an internally coherent framework for objective morality. But it faces challenges:

1. The Metaphysical Challenge: How do normative facts exist? "Free floating" seems an unsatisfactory answer.

2. The Obligation Challenge: Even if morality is objective, why should I be bound by it?

3. The Explanatory Challenge: Theism provides unified explanation (morality + consciousness + order + purpose), while secular realism appears fragmented.

4. The Moral Knowledge Challenge: How do we know moral facts if they are non-natural? Moral intuition may be misleading.

Where We Stand in This Debate Today

The debate between secular and theistic moral realism remains alive in the academy. There is no consensus. Both positions have strong defenders and serious critics.

From the perspective of "rational consideration" (rajḥān ʿaqlī): Secular realism is logically possible, but it pays a metaphysical price (obscure floating facts) and practical price (weak obligation). Theistic theory provides simpler and more comprehensive explanation, but requires accepting God's existence.