What is the difference between conceiving of laws as "descriptive" (summarizing regularities) and "necessary" (fundamentally governing reality), and which conception is more suitable for the theistic argument?

The debate about the nature of natural laws — whether they are mere descriptions of what we observe, or real forces governing reality — is among the deepest questions in philosophy of science. This question has direct implications for theistic arguments from order and cosmic fine-tuning, and deserves careful analysis that goes beyond superficial slogans.

Inadequate Responses to Avoid

From some believers:

"Laws directly prove the existence of a Lawgiver." A misleading oversimplification. Even if laws are necessary and governing, the transition from "law" to "lawgiver" requires additional logical steps. An atheist physicist might accept the necessity of laws without accepting a lawgiver for them.

"Descriptive laws make science meaningless." Inaccurate. David Hume, Ernst Mach, and Bertrand Russell — great philosophers — defended the descriptive conception without denying the value of science. Their position has costs, but it is not "meaningless."

From some naturalists:

"Laws are merely human descriptions, and talk of their necessity is metaphysical delusion." A hasty reduction. Contemporary philosophical debate shows that both conceptions have their justifications and costs. Respected philosophers of science like David Armstrong and Tim Maudlin defend the necessity of laws with strong technical arguments.

"The necessary conception of laws entails theism." A logical error. Philosophers like Armstrong adopt the necessity of laws within a purely naturalistic framework. Necessary laws might be interpreted as intrinsic properties of nature itself, without need for an external source.

Why These Responses Are Inadequate

They share a disregard for the technical complexity of the debate. The question is not "which is absolutely correct?" but "what are the costs and benefits of each conception? And how does this affect theistic arguments?"

The Descriptive Conception: Laws as Summaries

Proponents of the descriptive conception (Humean/Regularity View) see laws as merely economical summaries of observed regularities. Newton did not "discover" a governing force, but rather observed that bodies move in regular ways, and formulated equations summarizing these regularities.

Arguments for the Descriptive Conception:

First: Ontological simplicity. We need not assume obscure metaphysical entities (forces, necessities, governing relations). All we observe are regular events, and laws are merely descriptions of these regularities.

Second: Avoiding metaphysical problems. If laws "govern" nature, how do they do so? Where do they exist? How do they compel matter to obey? The descriptive conception avoids these thorny questions.

Third: Compatibility with the development of science. Scientific laws change (from Newton to Einstein). This is easier to understand if they are merely improvable human descriptions, not fixed metaphysical truths.

Problems with the Descriptive Conception:

First: The problem of induction. If laws are merely summaries of the past, what justifies our expectation that they will continue? Why do we trust that the sun will rise tomorrow? The descriptive conception provides no basis for scientific prediction.

Second: Circularity. We define a "law" as a regularity that continues. But how do we distinguish "lawlike" regularities from coincidences? We say: the lawlike ones are those that support counterfactual predictions. But this brings us back to some necessity in laws.

Third: Failure to explain scientific success. Why does mathematics succeed in describing nature with amazing precision? The descriptive conception makes this success an unexplained miracle.

The Necessary Conception: Laws as Governing Forces

Proponents of the necessary conception (Necessitarian/Governing View) see laws as necessary relations between cosmic properties. The law of gravitation is not merely an observation that bodies attract each other, but a necessary relation between mass and acceleration.

Arguments for the Necessary Conception:

First: Explaining regularity. Why do electrons always carry the same charge? The necessary conception provides an answer: because this is part of the electron's necessary nature. The descriptive conception leaves us with unexplained regularity.

Second: Supporting counterfactual predictions. We say with confidence: "If I dropped this pen, it would fall." This confidence is logical if gravity is a necessary law, not merely an inductive generalization.

Third: Compatibility with scientific practice. Scientists search for "why" things happen, not just "how." They assume that nature is governed by deep principles, not merely regular coincidences.

Problems with the Necessary Conception:

First: Metaphysical obscurity. What is the nature of this "necessity"? How do abstract laws compel physical events? Armstrong suggests they are relations between universals, but this leads us into the mazes of realism about universals.

Second: The problem of changeability. If laws are necessary, how do we explain that different laws seem logically possible? Why is the speed of light this value and not another?

Third: Tension with modern physics. String theory suggests multiple universes with different laws. This is easier to understand with the descriptive conception than with the necessary one.

Implications for Theistic Arguments

With the Descriptive Conception:

If laws are mere descriptions, then the question "why these regularities?" becomes acute. Fine-tuning of constants becomes more pressing: why, out of all possible regularities, do we find those that permit life? The believer finds an opportunity here: unexplained regularities need an external source.

But the naturalist might reply: perhaps regularities are merely brute facts. Or perhaps we are in one universe among infinite universes with different regularities.

With the Necessary Conception:

If laws are necessary, then the question shifts: what is the source of this necessity? Swinburne argues that natural necessities need explanation, and God is the simplest explanation. Complex and fine-tuned necessary laws point to a designing mind.

But the naturalist might reply: necessity might be intrinsic to nature itself. Armstrong and others build naturalistic metaphysics of necessary laws.

Contemporary Advanced Positions

The "Ontic Structural Realism" current with James Ladyman suggests that laws are not separate from reality — mathematical structure is reality. This transcends the descriptive/necessary duality.

The "Quantum Laws of Nature" current explores how quantum mechanics changes our understanding of laws. Perhaps laws are intrinsically probabilistic, not deterministic.

The "Precise Theistic Arguments" current develops the argument carefully: regardless of the adopted conception, the existence of regular mathematical laws that permit complexity needs explanation, and theism provides a coherent explanation.

Where We Stand in This Debate Today

There is no consensus on the nature of laws. Both conceptions have strong proponents and solid arguments. For the theistic argument, the matter is not the victory of one conception, but how to deal with both:

— With the descriptive conception: amazing unexplained regularities need explanation.
— With the necessary conception: the source of necessity and complexity needs explanation.

The reasonable position, within the method of rational preponderance (rajḥān ʿaqlī), is to acknowledge that both conceptions raise deep questions to which theism can contribute answers, without claiming decisive proof. The debate continues, and arguments evolve with the development of our understanding of physics and philosophy of science.

For Advanced Reading

— Advanced level: Structural realism and transcending the descriptive/necessary duality
— Advanced level: Laws of nature in quantum physics and general relativity
— David Armstrong, What Is a Law of Nature? (Cambridge UP, 1983)
— Tim Maudlin, The Metaphysics Within Physics (Oxford UP, 2007)
— Helen Beebee, "The Non-Governing Conception of Laws" (2000)
— John Foster, The Divine Law