Program / Course 19: Modern Challenges / Lesson 1.3
What you will learn
- Define philosophical naturalism and separate it from methodological naturalism and from science itself.
- State the main arguments naturalists give for their view.
- Describe the main alternatives: supernaturalism, dualism, idealism and theism.
- Explain why the question cannot be settled by science alone.
The big idea
Philosophical naturalism is the claim that nature is all there is: nothing exists outside the physical world and its laws, and no god or spirit acts upon it. It is a philosophy, not an experiment. Scientists of every belief practice a different thing, called methodological naturalism, which simply studies natural causes. Naturalists argue that their view is simplest and best supported by the success of science. Others reply that the success of science does not show that nothing else exists.
Key terms
- Philosophical (or metaphysical) naturalism
- The view that the natural world is all that exists, and that there are no supernatural beings or forces.
- Methodological naturalism
- The practice of explaining natural events by natural causes in scientific work, without a claim about whether anything else exists.
- Supernatural
- What lies beyond or above the natural order, such as God, angels or a soul. Christians hold that God is not part of nature but its Creator.
- Materialism (or physicalism)
- The view that everything is matter and energy, or is fixed by the physical. Most naturalists hold it, though some want a broader idea of nature.
- Dualism
- The view that mind and body, or soul and body, are distinct. Christians who hold it point to the soul.
- Occam’s razor
- The rule of thumb that one should not multiply explanations beyond what is needed. It is named for William of Ockham, a fourteenth century friar.
- Metaphysics
- The branch of philosophy that asks what exists and what it is like.
Background
Some Greek thinkers before Socrates tried to explain the world by natural principles such as water, air and atoms. The Roman poet Lucretius gave a materialist account in his poem On the Nature of Things. Christian theology, though, often welcomed the study of nature because it taught that the world is a good creation with its own order. Medieval thinkers such as Aquinas and Albert the Great wrote on nature, and historians of science have often noted that many founders of modern science, such as Kepler, Boyle and Newton, were believers.
Naturalism as a full philosophy gained strength in the nineteenth century as the sciences advanced, and above all after Darwin. In the twentieth century many philosophers adopted it as the working assumption of their field. Today naturalism is common in universities, though philosophers who are theists, idealists or dualists remain numerous and respected. A recent survey of professional philosophers found that a majority reported being atheists, while a sizable minority were theists. The result shows how contested the matter is.
Step-by-step explanation
Step 1: Two kinds of naturalism
Methodological naturalism is a rule of method: when you study the weather or a disease, look for natural causes, and test them. A Christian doctor, physicist or biologist can follow it with no inconsistency, and most do. A Christian can say that God sustains all things and also that rain falls because of pressure and temperature.
Philosophical naturalism is a claim about reality. It says there is nothing else to find. This is a conclusion that no laboratory result can prove, because the laboratory only handles what can be measured. For this reason, careful writers on both sides insist on separating the two.
Step 2: The naturalist’s arguments
The first argument is from success. Natural explanations have replaced supernatural ones in one area after another, such as lightning, disease, planetary motion and the origin of species. Naturalists conclude that the pattern will continue. The second argument is simplicity: if natural causes suffice, adding a god is unnecessary. The third is the argument from dependence of mind on brain. Damage to the brain changes personality and memory, so, they say, the mind is likely a product of the brain.
A fourth argument is from the failure of religion to agree. If many religions disagree, perhaps none has special access to truth. Each of these arguments is serious, and each has been answered.
Step 3: Alternatives to naturalism
Theism holds that there is one personal God who made the world and acts in it. Christian theism adds that God has become man in Christ. Deism holds that God made the world but does not intervene. Idealism, held by thinkers such as Berkeley and Hegel in different forms, holds that mind or spirit is basic and matter secondary. Dualism holds that there are both matter and mind. Some people hold views such as pantheism, in which God and the world are one.
These views do not deny science. Berkeley, for instance, thought that ordinary physical objects exist and can be studied. They deny that science alone settles what exists.
Step 4: Why science cannot settle it
Science asks how things happen within the world, and does so by tests that any competent person can repeat. Whether the world as a whole has a cause or a purpose is a different sort of question. A naturalist may reply that if it cannot be tested, it should be set aside. But the principle that only testable claims are meaningful cannot itself be tested. This was the difficulty with logical positivism, the early twentieth century school that proposed it, and that school largely collapsed.
Both sides can then make arguments from philosophy and experience. The theist points to the existence of the universe, its order, consciousness, moral knowledge and religious experience. The naturalist replies that each may in time be given a natural account, or that the questions do not require an answer. Neither side has the right to say that the matter has been closed.
- Is the speaker describing a method of science or a claim about all reality?
- What evidence would count against naturalism, and what would count for theism?
- Does the argument from success show that supernatural explanations are always wrong?
- Does the naturalist account of mind explain why the mind can know truth?
- What does the theist give up if he accepts the methods of science fully?
- Which side bears the burden of proof, and why?
Examples
A Christian geologist
A geologist studies a rock formation and explains it by erosion over millions of years. She prays on Sundays and believes God made the world. She uses methodological naturalism at work and rejects philosophical naturalism in her worldview. (A constructed example.)
A naturalist physician
A doctor believes that the mind is what the brain does, that death ends consciousness and that nothing lies beyond nature. He bases this on his work with patients with brain injuries. He is honest that he cannot prove it and treats it as the most reasonable view. (A constructed example.)
An argument that moves between the two
A textbook says that science explains everything by natural causes and therefore there is no God. The first half is a claim about method. The conclusion is a claim about reality that does not follow. (A constructed example.)
Different perspectives
Naturalist
Naturalists hold that their view follows the evidence and does not begin with a bias. They say they would change their minds if reliable evidence for the supernatural appeared. They also say that many things once attributed to spirits or gods now have natural explanations, and they believe the trend is a reason for confidence.
Catholic
The Catholic tradition holds that reason can show that God exists, as Aquinas argued, and so it rejects naturalism as a mistake in philosophy. At the same time it affirms the value of science, and the First Vatican Council taught that faith and reason cannot truly be in conflict because the same God is the author of both. Catholics vary in how strongly they press the philosophical proofs.
Orthodox
Orthodox theology stresses that God is not an item in the universe but beyond all that he made, and that he is known above all by participation and worship. Orthodox writers such as David Bentley Hart argue that naturalism fails to account for being, consciousness and meaning, while Orthodox scientists and priests work without conflict in the sciences.
Protestant
Protestants differ. The Reformed philosopher Alvin Plantinga argues that naturalism combined with evolution undermines confidence in human reasoning, and that belief in God can be properly basic without proof. Others, in the tradition of Karl Barth, doubt whether philosophical arguments for God are needed or helpful, since God is known by his self-revelation.
Why it matters
The step from science to the claim that nature is all there is feels small, and many people take it without noticing. A student who sees the gap can honor science fully while seeing that the larger question remains. The same care helps with a believer who thinks that accepting science is a betrayal of faith.
Common misunderstandings
Misunderstanding: Accepting science means accepting naturalism.
Correction: Science uses methodological naturalism as a working rule. It does not conclude that nothing exists beyond nature. That is a separate philosophical claim.
Misunderstanding: Naturalists are closed-minded about evidence.
Correction: Many naturalists are open to being persuaded. The disagreement is over what counts as good evidence and how to weigh it.
Misunderstanding: Religious belief has always opposed natural explanation.
Correction: Christians such as Albert the Great, Kepler and Boyle studied nature as God’s work. Opposition arose in particular disputes, not as a rule.
Misunderstanding: Naturalism has been proven by science.
Correction: It is a philosophical position that its defenders argue for. Many scientists and philosophers, believers and not, say the evidence does not decide the matter.
Knowledge check
What is the difference between methodological and philosophical naturalism?
Methodological naturalism is a rule of scientific method: look for natural causes and test them. Anyone can follow it, whatever his beliefs about God. Philosophical naturalism is the claim that nature is all there is and nothing supernatural exists. The first is part of doing science. The second is a belief about reality that science cannot test.
Give two arguments that naturalists make for their view.
One is the argument from success: natural explanations have replaced supernatural ones in many areas, so the trend will probably continue. Another is the dependence of mind on brain: since damage to the brain alters thought and personality, the mind is probably a product of the brain. Others appeal to simplicity and to religious disagreement.
Name three alternatives to naturalism.
Theism holds that a personal God made and sustains the world. Dualism holds that mind and matter are both real and distinct. Idealism holds that mind or spirit is more basic than matter. Deism and pantheism are further alternatives. Each of them can be held together with acceptance of ordinary science.
Why can’t science alone decide between naturalism and theism?
Science studies events within the world by measurable, repeatable tests. The questions of whether the world has a cause, a purpose or anything beyond itself are philosophical. The claim that only testable statements are meaningful cannot itself be tested, and the school that proposed it, logical positivism, was largely given up.
Think it through
- Where have you heard a claim about method turned into a claim about reality?
- Which of the four naturalist arguments do you find most forceful, and what is the best reply?
- What would it take to change your mind about the supernatural, and is the same true for a naturalist?
- Does your view of mind and body influence what you think about death?
Independent assignment
Method or worldview
In your notebook, take three statements from a popular science article, a textbook or a documentary. For each, decide whether it is a claim of method (how scientists work), a finding (a result), or a worldview claim (about what exists). Write 300 to 500 words explaining your decisions, with special care for any statement that mixes categories. Do not post or send it.
Further study
- Stanford Encyclopedia of Philosophy, Religion and Science Read the sections on methodological and metaphysical naturalism.
- Alvin Plantinga, Warranted Christian Belief Read selectively for the argument that belief in God can be rational without proof.
- David Bentley Hart, The Experience of God: Being, Consciousness, Bliss Read selectively for an argument that being, consciousness and bliss point beyond nature.
- Richard Swinburne, The Existence of God Read selectively for a cumulative case that engages naturalism directly.
- Thomas Aquinas, Summa Theologiae I, Q. 2: The Existence of God Read the five ways in their short form.
- Psalm 19:1 The heavens declare the glory of God.
- Romans 1:20 Paul says that God’s invisible things are clearly seen through the things that are made.