Deductive, Abductive, and Inductive Reasoning

 The Moral Law tells us the tune we have to play: our instincts are merely the keys.

– C.S. Lewis

There are several versions of the Moral Argument for the existence of God.  What underlines them all is the affirmation that morality is either subjective (found within one’s self) or objective (grounded outside of one’s self).  

Deductive Argument:

A popular syllogism of the Moral Argument is that which has been presented by Dr. William Lane Craig as presented in the following deductive argument:

P1 If God does not exists then objective moral values and duties do not exist.

P2 Objective moral values and duties do exist.

C1 Therefore, God exists.

Dr. Craig is a prominent Christian philosopher and theologian known for his defense of the existence of God using various arguments, including the Moral Argument.  Dr. Craig’s argument is based on the idea that objective moral values and duties exist, and the best explanation for their existence is God. 

He argues that without God, there is no objective basis for moral values and duties, and morality becomes subjective or arbitrary, and thus illusory. This argument has been debated extensively in philosophical circles and continues to be a topic of discussion in the philosophy of religion.  Here are a few links to Dr. Craig’s debates with atheists on this very subject: Craig vs Wielenberg; Craig vs Harris; Craig vs Kagan

“Unless there is a God, all morality is just opinion and belief. And virtually every atheist philosopher has acknowledged this.”
— Dennis Prager

Abductive Argument:

A slightly more modest and abductive version would be as follows:

P1 There are objective moral obligations (such as kindness and goodness).

P2 The best explanation of objective moral obligations is (probably) God.

C1 Therefore, (probably) God exists.

This syllogism argues from inference to the best explanation.   Dr. David Baggett, who is a contemporary Christian philosopher and who has contributed to the moral argument for the existence of God (see his book, Good God: The Theistic Foundations of Morality) argues abductively. Dr. Baggett, along with his colleague Jerry L. Walls, has developed what is sometimes called the “moral argument from goodness.” This argument suggests that objective moral values and duties exist and that the best explanation for their existence is the existence of God.

Dr. Baggett’s version of the moral argument emphasizes the nature of goodness itself, arguing that moral goodness is best understood as grounded in the nature of God. According to Baggett, moral values such as love, justice, and compassion have an objective reality that points towards the existence of a morally perfect being, which is God. In essence, Dr. Baggett’s moral argument highlights the connection between the existence of objective moral values and duties and the existence of God as their ultimate source and foundation.

Where there is no “moral gravity” – that is, no force that draws us to the center – there is spiritual weightlessness. We float on feelings that will carry us where we never meant to go; we bubble with emotional experiences that we often take for spiritual ones; and we are puffed up with pride. Instead of seriousness, there is foolishness. Instead of gravity, flippancy. Sentimentality takes the place of theology. Our reference point will never serve to keep our feet on solid rock, for our reference point, until we answer God’s call, is merely ourselves. We cannot possibly tell which end is up. Paul calls them fools who “…measure themselves by themselves, to find in themselves their own standard of comparison!”

– Elizabeth Elliot

Inductive Argument:

An inductive argument for the existence of God based on morality could be as follows:

P1 Throughout human history and across various cultures, there has been a consistent belief in the existence of objective moral values and duties.

P2 The existence of objective moral values and duties suggests that there is a transcendent source or foundation for these values beyond human invention or societal norms.

P3 It is more reasonable to posit that this transcendent source is God, defined as a higher, moral authority, than to attribute objective morality to random chance or human evolution alone.

C1 Therefore, the pervasive belief in objective moral values and duties, and the existence of these values, provide strong inductive evidence for the existence of a moral, transcendent God.

This argument does not aim to prove the existence of God definitively, as in deductive reasoning, but rather makes a probabilistic inference based on the observed correlation between objective morality and the belief in a higher moral authority.

In all three syllogisms the meaning of God is Anselmain, that is to say that God is understood as a necessary, maximally great Being of whom none is greater, (see Ontological Argument).

By moral values the meaning is what is good or bad. By duties the meaning is what is right or wrong.

If moral values and duties are objective they exist regardless of what we think, say, or do. Being objective they must be based in something that is transcendent, who is the basis or foundation on which we perceive them. A being who is absolute goodness and maximally great in attributes. This being would want His creation to reflect that goodness and would (as Dr. Alvan Plantinga notes) “one way or another, legislate them” for His creation.

The Christian theist, such as myself, would argue that God is that being, that He has legislated them first in the hearts of humankind (Psalm 19:1; Romans 1:19-21; Philippians 2:13) and has revealed them through the Person of Jesus Christ as God incarnate (John 1:1; 14:23; 20:28; 2 Corinthians 5:17-20). So we speak of two books: The book of Nature and the book of Scripture. Of course, other forms of theism can likewise use the moral argument provided their concept of God includes His moral nature.

The moral absolutes rest upon God’s character. The moral commands He has given to men are an expression of His character. Men as created in His image are to live by choice on the basis of what God is. The standards of morality are determined by what conforms to His character, while those things which do not conform are immoral.

– Dr. Francis Schaeffer

Alvin Plantinga and EAAN:

Dr. Alvin Plantinga, a renowned philosopher who taught at Notre Dame, has also contributed significantly to the moral argument for the existence of God. Dr. Plantinga’s version of the moral argument often focuses on the idea that if God does not exist, objective moral values and duties would not have a sufficient foundation.

One of Plantinga’s key contributions to the moral argument is his formulation of what’s known as the evolutionary argument against naturalism (EAAN). This argument suggests that if naturalism—the view that only the natural world exists—is true, then our cognitive faculties, including our moral intuitions, are the product of blind evolutionary processes aimed at survival rather than truth. As a result, if naturalism is true, there is no reason to trust that our moral intuitions are reliable or that objective moral values and duties exist.

Plantinga argues that the existence of objective moral values and duties is more plausible within a theistic framework, where God serves as the foundation for morality and provides a basis for our moral intuitions being reliable.

A syllogism of Plantinga’s argument has been offered by philosopher Dr.  Mark Linville and is as follows:

P1 If evolutionary naturalism is true, then human morality is a by-product of natural selection.

P2 If human morality is a by-product of natural selection, then there is no moral knowledge.

P3 There is moral knowledge.

C1 Therefore, evolutionary naturalism is false.

See: Mark Linville, “The Moral Argument,” in The Blackwell Companion to Natural Theology, eds. William Lane Craig and J. P. Moreland (Oxford: Blackwell Publishing Ltd., 2009), 392-395. 

A defense of this argument is presented by Dr. Zach Breitenbach in his 4 Part article series The Case That Our Moral Knowledge Points Towards God found on the Moral Apologetics website.  Dr. Breitenbach is the Director of the Worldview Center at Connection Pointe in Brownsburg, IN and the former Associate Director of Room For Doubt.

Overall, Plantinga’s contribution to the moral argument highlights the tension between naturalism and the existence of objective moral values and duties, suggesting that theism provides a more coherent foundation for morality.

“Thomas Aquinas and John Calvin concur on the claim that there is a kind of natural knowledge of God (and anything on which Calvin and Aquinas are in accord is something to which we had better pay careful attention).”

– Dr. Alvin Plantinga

Addressing 5 Possible Objections:

Objection 1 Morals Are Subjective: 

Some object believing that moral values and duties are subjective – that we make our own truth. But if this is true then those things which we perceive as right or wrong, good or bad are really illusory – they cannot be concrete or else they would be objective. 

As atheist philosopher Michael Ruse stated, “I appreciate that when somebody says ‘Love thy neighbor as thyself’ they think they are referring above and beyond themselves . . . Nevertheless, . . . such reference is truly without foundation. Morality is just an aid to survival and reproduction, . . . and any deeper meaning is illusory.” (Ruse, The Darwinian Paradigm, 1989, pp 262, 268-269). 

If this position is true then social justice, equal rights, abolition of slavery are not really moral obligations and rape, child abuse, and murder are not really wrong. The objection, as with several others, is self-defeating. If truth is subjective does that apply to the statement “truth is subjective”? Likewise, if moral values and duties are subjective, is not that claim itself subjective? Therefore, the objection defeats itself.

Objection 2 Morals Are Societal: 

Some believe that morals are just the product of group think, what is good or bad for the society. But if this is true then if society approves of an action it is morally right, and evils such as flying planes into buildings, or sending Jews, Gypsies, and homosexuals to concentration camps to be gassed or starved to death would not be wrong because of societal approval. While everyone would agree that there are societal mores and cultural differences – these are a far cry from good and evil, right and wrong.

Objection 3 Morals Are The Product Of Naturalistic Evolution: 

Do you really want survival of the fittest to be the foundation of morality? How could we really trust such actions as truly right or wrong, good or bad? As Plantinga notes above and illustrated by Linville, the position is self-defeating because on naturalism, ALL our beliefs (moral values or any belief) have been selected for survival value, not grounded truth, and are therefore unwarranted – in particular the belief in naturalism and the socio-biological account of moral belief (Plantinga, Warrant and Proper Function, 1993, pp. 216-237).

Objection 4 An Argument Is Not Evidence: 

This is a very general objection that has been raised by some when any argument for the existence of God is presented. Such a statement is, of course, self-defeating. To say, “an argument is not evidence” is to use an argument as evidence. Additionally, logical arguments are used as evidence in courts of law, science, and philosophy.

Objection 5 The Euthyphro Dilemma: 

First recorded by Plato, the dilemma is named after a character named Euthyphro in Plato’s dialogues and asks the question (1) Is something good because God wills it? Or (2) does God will something because it is good? Dr. Craig notes of the Dilemma “can thus be construed as an argument for Atheistic Moral Platonism . . . This suggests that the dilemma allegedly forcing us to such a position is a false one and that we may escape the horns of the dilemma by finding a third alternative” (Reasonable Faith, p. 181). That third alternative is to say God wills something because He is good (which beings us back to the Ontological Argument and God being a maximally great, necessary being.

 The ultimate test of a moral society is the kind of world that it leaves to its children.

– Dietrich Bonhoeffer

Conclusion:

Dr. Baggett notes, 

“In light of the depth and ingression of moral convictions and clarity of certain moral apprehensions, someone might respond to skepticism about moral obligations along these lines: (1) Rational skepticism about moral obligations must depend on reasons. (2) Those reasons are not as obviously true as are moral obligations themselves. (3) So it is not rational to be a skeptic about moral obligations.” (Two Dozen (or So) Arguments for God, p. 264)

I have presented a brief defense of the moral argument. I have also listed 5 possible objections and addressed them. If an argument is to be successful against the moral argument then one or both of the premises in the above arguments need to be shown more likely false than true, otherwise we have good reason to accept the premises and adopt the conclusion that God exists.

Admittedly, the moral argument cannot be fully addressed in a brief article and I would encourage the reader to investigate moral arguments for God’s existence. 

It should also be noted that the argument from morality is not claiming that belief in God is necessary for objective morality (both theists and atheists can be moral). It is claiming that God is necessary for objective morality to exist. As Dr. Richard Taylor notes, “the concept of moral obligations [is] unintelligible apart from the idea of God. The words remain, but their meaning is gone.” (Taylor, Ethics, Faith, and Reason 1984, pp. 83-84).

Jesus had little trouble reaching the harlots, the thieves, robbers, criminals, outcasts, and sinners of society, including the tax collectors and the extortionists, but He had an almost impossible time reaching the religious, self-righteous, moral people who were under the illusion and self-deception that because of their goodness, everything was OK between them and God. They recognized no sin, so they needed no Savior. That is always the danger of morality. Morality creates an illusion of safety when in fact the person who is moral may be in the greatest danger of all.

– Dr. John MacArthur