Contemporary Debates in Philosophy of Religion

The philosophy of religion is a living, dynamic discipline. This lesson examines four major contemporary debates: Plantinga's case for warranted Christian belief, William Lane Craig's revival of the Kalam cosmological argument, the challenge of the New Atheism (particularly Dawkins), and the responses of Christian philosophers such as Alister McGrath. These debates shape the current landscape of the philosophy of religion and demonstrate the ongoing vitality of the discipline.

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Plantinga's Warranted Christian Belief

The Warrant Trilogy

Alvin Plantinga (b. 1932) developed his mature epistemology across three major works: Warrant: The Current Debate (1993), Warrant and Proper Function (1993), and Warranted Christian Belief (2000). The trilogy represents the most sophisticated defence of the rationality of Christian belief in contemporary philosophy.

What Is Warrant?

Plantinga defines warrant as the quality that distinguishes genuine knowledge from mere true belief. A belief has warrant when it is produced by cognitive faculties that are:

1. Functioning properly — operating as they were designed to operate
2. In an appropriate epistemic environment — the environment for which they were designed
3. According to a design plan aimed at the production of true beliefs
4. Successfully — the design plan is reliable, and the belief produced is true or likely true

Key Definition: Warrant — In Plantinga's epistemology, the quality or quantity that, when added to true belief, yields knowledge. A belief is warranted when it is produced by properly functioning cognitive faculties operating in an appropriate environment according to a design plan aimed at truth.

The Extended Aquinas/Calvin Model

Plantinga proposes what he calls the Extended Aquinas/Calvin (A/C) Model for the warrant of Christian belief:

Component	Description
Sensus divinitatis	A natural cognitive faculty that produces belief in God when triggered by appropriate experiences (nature, moral awareness, gratitude). Damaged by sin but not destroyed
The Internal Instigation of the Holy Spirit (IIHS)	The Holy Spirit works through Scripture, preaching, and experience to produce specifically Christian beliefs (the Trinity, the Incarnation, salvation through Christ). This is how the articles of faith become warranted
Scripture	The principal means through which the Holy Spirit produces and sustains Christian belief. Scripture is "self-authenticating" — it carries its own evidence of divine authority

The De Jure / De Facto Distinction

Plantinga draws a crucial distinction:

• De facto objections to Christianity claim that Christianity is false — God does not exist, Jesus did not rise from the dead
• De jure objections claim that Christianity is irrational, unjustified, or unwarranted — even if it happens to be true, believing it is epistemically irresponsible

Plantinga argues that there is no successful de jure objection to Christianity that is independent of the de facto question. If Christianity is true — if God exists, the sensus divinitatis is real, and the Holy Spirit works through Scripture — then Christian belief is warranted. The only way to show that Christian belief is unwarranted is to show that it is false. The epistemological question reduces to the metaphysical question.

Criticisms of Plantinga

• Circularity — Plantinga's defence of Christian belief assumes the truth of Christianity. If the A/C model is correct, Christian belief is warranted. But whether the A/C model is correct depends on whether Christianity is true. This appears viciously circular
• The Great Pumpkin objection — any belief system could construct a parallel model (belief in the Great Pumpkin is produced by a sensus pumpkinitatis). If the A/C model works for Christianity, why not for absurd beliefs?
• The problem of religious diversity — Muslims, Hindus, and Buddhists could construct analogous models. If every religion can defend its rationality with equal logical force, the defence provides no way of choosing between them
• Empirical concerns — the sensus divinitatis is not empirically detectable. Critics argue it is an ad hoc postulate designed to protect theistic belief from criticism

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William Lane Craig and the Kalam Revival

Craig's Programme

William Lane Craig (b. 1949) is the most prominent defender of the Kalam cosmological argument in contemporary philosophy. Craig has developed and defended the argument in numerous books, articles, and public debates, making it central to contemporary natural theology.

The Argument

1. Everything that begins to exist has a cause
2. The universe began to exist
3. Therefore, the universe has a cause

Craig's Defence of the Premises

Premise 1: Craig argues that the causal principle — ex nihilo nihil fit ("from nothing, nothing comes") — is one of the most fundamental metaphysical truths. It is confirmed by universal experience: we never observe things popping into existence uncaused. To deny premise 1 is to abandon the basic intelligibility of the world.

Premise 2: Craig offers both philosophical and scientific arguments:

Type	Argument
Philosophical	An actually infinite number of past events is impossible. An actual infinity leads to absurdities (Hilbert's Hotel — a fully occupied hotel with infinitely many rooms can accommodate infinitely many new guests). If the past is not infinite, the universe must have begun to exist
Scientific	Big Bang cosmology confirms that the universe began approximately 13.8 billion years ago. The second law of thermodynamics implies that the universe is running down — and if it is running down, it must have started. The Borde-Guth-Vilenkin theorem (2003) demonstrates that any universe that has been expanding on average must have a beginning

The Properties of the Cause

Craig argues that the cause of the universe must be:

• Timeless — since it created time
• Spaceless — since it created space
• Immaterial — since it created matter
• Enormously powerful — since it created the entire universe from nothing
• Personal — since only a personal agent can make a free decision to create something from nothing. An impersonal, mechanistic cause would either produce the effect eternally or never produce it at all; a personal agent can freely choose to act

Criticisms of Craig

• Quantum mechanics challenges premise 1 — virtual particles appear and disappear without deterministic causes at the subatomic level. If uncaused events occur in nature, the causal principle is not universal
• The concept of "nothing" — Craig's argument assumes that "before" the Big Bang there was literally nothing. But our concepts of time, causation, and "before" may not apply to the state prior to the Big Bang
• The Hilbert Hotel argument — mathematicians accept actual infinities as coherent mathematical concepts. Craig's rejection of actual infinities may reflect a philosophical preference rather than a logical necessity
• Alternative cosmologies — the Hartle-Hawking "no boundary" model suggests the universe may have no temporal beginning even though it is finite in age. Cyclic models and the multiverse hypothesis offer alternatives to a single beginning
• The leap to God — even if the argument establishes a first cause, the identification of this cause with the personal God of Christianity requires additional argument that the Kalam alone does not provide

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The New Atheism: Dawkins and Others

The Movement

The New Atheism emerged in the early 2000s with the publication of several bestselling books attacking religion:

Author	Book	Year
Sam Harris	The End of Faith	2004
Richard Dawkins	The God Delusion	2006
Daniel Dennett	Breaking the Spell	2006
Christopher Hitchens	God Is Not Great	2007