3.3.2 - Teleological and design arguments

The Design Question

A design argument begins from a familiar thought: some features of the world look ordered, purposive or regular in a way that seems to call for explanation. The philosophical question is not just whether nature is impressive. It is whether order in nature gives evidence for an intelligent designer.

These arguments are a posteriori because they start from experience of the world, not from a definition of God.

The AQA issue is especially about logical form. A design argument may be:

A very general design argument can be reconstructed like this:

1. P1: Some features of the natural world display order, purpose or regularity.
2. P2: In cases we understand well, order, purpose or regularity of that kind is often produced by intelligence.
3. P3: If a feature is best explained by intelligence in familiar cases, similar features in nature may also be evidence of intelligence.
4. Therefore, C: The order, purpose or regularity in nature gives evidence for an intelligent designer.

Hidden assumption: The order in nature is relevantly like the order produced by minds.
Inference type: Non-deductive; depending on the version, analogical, inductive or abductive.
Main pressure point: Whether the move from order to designer is strong enough, and what kind of designer it supports.

This conclusion is weaker than the conclusion of many ontological arguments. It does not usually claim that God must exist. It claims that observed order gives some reason, perhaps strong reason, to believe in a designer. The task is to understand how each named philosopher develops that move.

Hume's Design Argument From Analogy

Hume's Dialogues Concerning Natural Religion is a dialogue, so students should be careful: AQA asks for the design argument from analogy as presented by Hume, not a simple statement of Hume's own final view. The positive argument is mainly voiced by Cleanthes.

An analogy is a comparison used for reasoning. In an analogical argument, we move from a known case to a less familiar case because the two cases share relevant features. Cleanthes compares the world to a machine or human artifact. Human machines have ordered parts arranged for functions, and they are produced by intelligent minds. The natural world also appears to contain ordered parts arranged for functions. So, Cleanthes argues, the cause of nature is probably something like intelligence.

The argument can be reconstructed like this:

Claim at issue: Natural order is evidence of a designing intelligence.

1. P1: The natural world contains order and adaptation of means to ends.
2. P2: Human artifacts, such as machines, contain order and adaptation of means to ends.
3. P3: In the case of human artifacts, this order is caused by intelligent design.
4. P4: Like effects probably have like causes.
5. Therefore, C: The cause of natural order is probably an intelligent designer, somewhat analogous to the human minds that design artifacts.

Hidden assumption: The similarity between nature and human artifacts is relevant to their cause, not merely superficial.
Inference type: Analogical induction.
Main pressure point: How similar the world must be to an artifact for the inference to be strong.

The conclusion is important. This argument does not by itself prove an infinite, omnipotent, omniscient, omnibenevolent creator. It aims first at a designing intelligence similar in some respects to human intelligence, though vastly greater. That is why AQA asks students to attend to the strength of the conclusion and to the nature of God assumed or defended.

Hume's later parts in the set text raise problems about this analogy and about what attributes could be inferred from it. Those detailed objections are taught in the next lesson. Here, the key is to know the argument's positive structure: order in nature resembles order in artifacts; artifact order is caused by intelligence; therefore natural order probably has an intelligent cause.

Paley's Spatial Order And Purpose

Paley's Natural Theology develops a design argument from spatial order and purpose. Spatial order means that parts are arranged together at a time in a structured way. Purpose means that those parts are arranged so as to perform a function or achieve an end.

Paley's famous starting point is the contrast between finding a stone and finding a watch. A stone might not immediately demand an explanation in terms of a maker. A watch is different because its parts are arranged together so that they produce a useful result. The springs, wheels, glass and pointer are not merely heaped together. They are organised as means to an end.

Paley's point is not just that watches are complicated. Random complexity would not be enough. The crucial feature is purposive arrangement: parts are fitted together so that the whole performs a function.

Paley then extends the reasoning. In chapter 2, even if a watch could produce another watch, that would not explain the purposive arrangement of the watch-making mechanism itself. Reproduction would extend the need for explanation rather than remove it. In chapter 5, Paley applies the same pattern to natural organisms and organs, especially cases where parts appear fitted to useful ends.

The argument can be reconstructed like this:

Claim at issue: Purposive spatial order in nature is evidence of an intelligent designer.

1. P1: A watch contains parts arranged together for a purpose.
2. P2: Such purposive arrangement is best explained by an intelligent maker.
3. P3: Natural organisms and organs also contain parts arranged together for purposes.
4. P4: The same kind of purposive arrangement should receive the same kind of explanation unless there is a defeating reason.
5. Therefore, C: Natural organisms and organs are best explained by an intelligent designer.

Hidden assumption: Natural purposive order and artifact purposive order are similar in the respect that matters for explanation.
Inference type: Inductive and analogical; it can also be expressed abductively as an inference to the best explanation.
Main pressure point: Whether purposive arrangement in nature really requires the same kind of explanation as purposive arrangement in artifacts.

AQA accepts more than one accurately explained reading of Paley. A deductive reconstruction says that anything whose parts are organised for a purpose is designed; nature contains such things; design requires a distinct intelligent mind; therefore nature has a designer. The inference aims at entailment, but its soundness depends on the disputed universal design premise. An inductive or abductive reading instead treats purposive arrangement as probable evidence of intelligence or as best explained by it. An analogy with the watch is also creditworthy when its role is explained. State which reconstruction you use and match the claimed conclusion to it.

Swinburne's Temporal Order And Regularity

Swinburne shifts the focus from spatial order to temporal order. This is one of the most important distinctions in the lesson.

Swinburne calls spatial order regularities of copresence and temporal order regularities of succession. His central point is that Paley-style spatial order is not the only possible starting point. The lawlike regularity of the universe also needs attention.

Science explains particular events by using laws of nature. For example, a scientific explanation may cite a law plus earlier conditions to explain why a later event occurred. But if we ask why there are these most general laws, a normal scientific explanation seems to cite a further law, and then the question moves up a level. Swinburne argues that the existence of widespread temporal order can be explained by personal explanation.

The argument can be reconstructed like this: