What is the best way to show that the historic Christian faith and worldview are true? Christian apologists through the centuries have taken different approaches, but a powerful method gaining acceptance among Christian thinkers today is called best explanation or cumulative case apologetics.1
Most people recognize two basic forms of logical argumentation: deductive and inductive reasoning. But logicians sometimes speak of a lesser-known way of thinking called abductive reasoning. This third form of reasoning attempts to arrive at the best explanation for an event or series of facts. Unlike deduction, abduction provides something less than total certainty in its conclusion. Similar to induction, it yields only probable truth, and yet it doesn’t attempt to predict specific future, probable occurrences the way inductive reasoning does. Rather, it seeks to provide the most plausible broad, explanatory hypothesis.
Who Uses Abductive Reasoning?
Diagnosticians: moving from facts or data or events to a coherent, plausible explanation.
Abductive reasoning can be helpful in efforts to determine which argument for a given event is best. For example, one may use an abductive approach to decide which explanation best settles the controversy surrounding these two provocative apologetics issues:
1. What is the best explanation for Jesus Christ’s true identity? Was He man, myth, madman, menace, mystic, Martian, or messiah?
2. What is the best explanation for complex life on planet Earth? Was it more likely the result of divine creation or naturalistic evolution?
Criteria of Judgment
While logicians have formally set forth no hard and fast testing rules, they generally accept that the best explanatory hypothesis meets the following six criteria:
1. It offers a balance between complexity and simplicity (the simplest fully orbed explanation is best)
2. It is logically coherent
3. It corresponds to the facts (matches and makes sense of the facts)
4. It avoids unwarranted presumptions and ad hoc explanations
5. It can be tested
6. It successfully adjusts for possible counterevidence The hypothesis that scores highest on these criteria can be said to possess genuine explanatory power and scope.
A Cumulative Case for God
Just as a lawyer presents a brief in court or a physician arrives at a diagnosis by considering multiple symptoms and tests, a cumulative case consisting of multiple lines of converging evidence can be marshaled for the Christian worldview.
Consider Christian philosopher Richard Swinburne’s assessment of this approach:
Scientists, historians, and detectives observe data and proceed thence to some theory about what best explains the occurrence of these data…. We find that the view that there is a God explains everything we observe, not just some narrow range of data…. The very same criteria which scientists use to reach their own theories lead us to move beyond those theories to a creator God who sustains everything in existence.2
Historic Christianity’s Explanatory Scope
Christianity’s ability to account for and justify the many diverse and undeniable realities of life ranks as one of the strongest evidences that God exists and that the truth-claims of the historic Christian worldview are correct.
Christian theism best accounts for:
The Universe: its source and singular beginning, order, regularity, and fine-tuning Abstract Entities: the existence and validity of mathematics,
the laws of logic, and scientific models (which include their correspondence to the time-space universe as conceived in the mind of human beings)
Ethics: the existence of universal, objective, and prescriptive moral values
Human Beings: their existence, consciousness, rationality, free agency, enigmatic nature, moral and aesthetic impulse, and their need for meaning and purpose in life
Religious Phenomena: humankind’s spiritual nature and religious experience, the miraculous events of Christianity, and the unique character, claims, and credentials of Jesus Christ
This data (summarized above and expanded in 7 Truths That Changed the World) represents a cumulative case of compelling evidence for the God of the Bible; that is, while each of the individual points carries a certain logical or evidential force of its own, it is also true that the data taken collectively offers an even more formidable case in favor of the existence of the God of the Bible.
Other worldviews, both secular and religious, struggle to explain life’s critical realities. By logical inference the God of Christian theism best accounts for and explains the meaningful array of realities encountered in the
world and in life.
So how would the world look if the Christian worldview were indeed true? Based on the evidence, much the way it does look right now.
- Christian thinkers such as C.S. Lewis, Basil Mitchell, Richard Swinburne, and C. Stephen Evans have held this view. Paul D. Feinberg explains and defends a cumulative case approach in Five Views on Apologetics, Steven B. Cowan ed. (Grand Rapids: Zondervan, 2000).
- Richard Swinburne, Is There A God? (New York: Oxford University Press, 1997), 2.