Against the design argument

David Hume 1711 · 1776Neither causation nor induction can be proved: custom guides us.

What it claims

The order of the world does not prove the existence of the God of religions: at best it suggests a cause vaguely like an intelligence.

Why

An analogy is strong only if the cases resemble each other, and the universe resembles a human-made machine very little.

In short

"Against the design argument" is an argument by David Hume (Dialogues, II and V) on the question "Does God exist?" (answer: agnosticism). Its claim: The order of the world does not prove the existence of the God of religions: at best it suggests a cause vaguely like an intelligence. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P3). AskPhilosophy presents 3 objections, 3 of them with a documented reply, and the original text behind each premise, checked word for word.

Dialogues, II and V

Valid with an implicit premise

The design argument says: the world is ordered like a machine, so it has a designer. Hume, through Philo, does not claim that God does not exist. He shows that this argument yields at best a hypothesis, and nothing about the God of religions.

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.

Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P3, the computer finds a case where the analogy is weak and yet still proves: so one has to say that a weak analogy only makes a conjecture.

Valid with P3. The conclusion has two independent parts: P1, P2 and P3 strip the argument of its force as a proof; P4 strips it of its object, the one perfect God. Both would have to be refuted to save the argument as it stands.

Analogy. Seeing a house and concluding there was an architect is safe: we have watched thousands of houses being built. Seeing the universe and concluding there was an architect is judging a unique object that no one has ever seen come into being.

Objections

Each objection is a conversation: click to see who replies and where the debate stands.

Cleanthes (in the dialogue) attacks premise 3

No learned reasoning is needed: look at an eye, and the idea of a designer imposes itself with the force of a sensation. It is the objections that are abstract and artificial.

Hume replies

Hume In the dialogue

In the dialogue, Philo does not answer at the time: the narrator calls him "embarrassed and confounded". At the end of the book, he only grants that the cause of order bears "some remote analogy" to human intelligence.

Where the debate stands (our summary)In the text the answer stays unfinished: Philo is not refuted but does not press the point, and his final concession is deliberately vague. The dialogue names no spokesman, and commentators still discuss what Hume himself thought.

William Paley (the watch) 1802 · attacks premise 4

If I find a watch in a field, I conclude there was a watchmaker, even if it is imperfect and even if I have never seen a watch being made. Imperfection, or ignorance of the maker, takes nothing away from the evidence of design.

Hume replies

summary: their text is not yet in our corpus

No reply possible: objection raised in 1802, after the author's death (1776).

John Stuart Mill 1874

Summary: Mill does not follow Hume on everything: like Paley, he holds that the adaptations of living things are serious evidence for design. But on this precise point he sides with Hume: this evidence does not lead to the God of religions. It points rather to a designer of limited power, working with materials and forces he did not make. The world does not allow us to conclude that he is all-powerful or perfect.

Richard Swinburne 2004

Summary: Swinburne argues that, among hypotheses about a designer, the simplest is that of a being without limits (unlimited power and knowledge): positing a precise limit would add an arbitrary figure. Other things being equal, the simplest hypothesis is to be preferred.

Where the debate stands (our summary)Mill and Swinburne disagree on what the order of the world allows us to attribute to the designer: limited power (what the world shows, according to Mill) or unlimited power (the simplest hypothesis, according to Swinburne). The basic disagreement concerns the notion of simplicity and the weight of suffering and imperfection in this inference.

Fine-tuning argument (Swinburne, Collins) 1979 · attacks premise 2

The universe should not be compared to a house; probabilities should be computed instead: the physical constants that allow life are so improbable by chance that a designer becomes the most probable explanation.

Hume replies

summary: their text is not yet in our corpus see the argument

No reply possible: objection raised in 1979, after the author's death (1776).

Elliott Sober 2004

Summary: Sober grants the objection that one must reason in terms of probabilities, and even judges that Hume's criticisms based on analogy do not touch this version. But he argues that one cannot say fine-tuning is more probable if a designer exists unless one has independent information about that designer's goals and abilities. He thus joins Hume's doubt about what can be known of the designer.

Richard Swinburne 2004

Summary: Swinburne argues that a perfectly good God has reasons to create an ordered universe that harbours conscious beings. Such a universe is therefore what one can expect if God exists: there is a prior reason about his goals.

Where the debate stands (our summary)The basic disagreement is about whether one can know, before observing the world, what a God would want to create. Defenders of fine-tuning appeal to reasons of goodness; their critics ask that such assumptions about God's goals be supported independently of the facts to be explained. The rest is in Collins's argument.

In the same family · Teleological (design)

The world has an architect (Balbus against Cotta)Cicero