A Brief Introduction to
Theories of Intelligent Design

by Craig Rusbult, Ph.D.

Originally, this was the second of four pages about Open Science:
Part 1: Methodological Naturalism 
Part 2: Theories of Intelligent Design 
Part 3: Can design be scientific?
Part 4: Open Science is Better Science (it includes Parts 1-3 and more) 

But my web-pages have been reorganized, and I suggest that you
read the comprehensive overview of Intelligent Design Theories.

    What is a design theory?  If you receive a radio signal — 2, 3, 5, 7, 11, 13, 17,... — and you conclude that "probably this string of prime numbers was the result of design, since it probably was not produced by undirected natural process, by a process that wasn't intelligently directed," you are proposing a theory of intelligent design.

    Evaluation of Design
  Can a design theory be evaluated?  Yes.  To explain the origin of a feature (an object, organism, system, situation,...) the two possibilities are non-design (with production by undirected natural process) and design (with production by design-directed action that converts a "design idea" into reality, into a designed feature we can observe).  Because a feature was produced by either design or non-design, we can use eliminative logic:  if we conclude that non-design is highly improbable, then design is highly probable.  Thus, evidence against non-design is evidence for design.  The reverse is also true, and evidence for non-design (for the sufficiency of undirected natural process in producing a particular feature) is evidence against a design of that feature.
    In this way, by testing for non-design we are testing for design.  We can conclude that a design theory is probably true (if all non-design theories seem highly implausible) or is probably false (if one non-design theory seems highly plausible).
    Can a design theory be proved?  No.  A design theory does not claim there is proof that non-design is impossible;  it only claims that, based on scientific evidence, design seems more probable.  This type of probability-based conclusion is consistent with the logic of science in which proof is always impossible, even though scientists can develop a logically justified confidence in the truth or falsity of a theory.  In science, a high level of confidence (not proof) is the goal of scientists when they evaluate a theory to determine whether it is worthy of acceptance.  { What about future developments in science? }

    Some theories of design, but not others, are controversial.  Can a "controversial" design theory be plausible?  Yes.  In several areas — including the origins of our universe and (*) the first life or complex life — scientific analysis shows that design deserves to be accepted, not as the only possible explanation, but as a potentially plausible explanation that is worthy of serious consideration and further development.
    * Notice the two kinds of design theories, claiming that either:  (1) design-directed action occurred at the beginning of history (to produce a universe with properties of nature that are "just right" for a wide variety of life-permitting phenomena, ranging from nuclear fusion and star formation to the chemistry of enzymes and DNA), or  (2) design-directed action occurred during history (as in the origins of life or complex life).  /  Although the first type of theory (proposing a design of nature) is interesting and important, in the rest of this page design will refer to the second type of theory, which claims "there is scientific evidence for design-directed action during the history of nature."

    Design and Controversy
  Are design theories always controversial?  No.  Theories of design are common, and scientists propose "design-directed action" to explain a wide variety of features such as bird nests, ant hills, predator-prey events, paintings on a cave wall, metal satellites in orbit, and faces on Mount Rushmore.  In many areas of science — for example, when a crime detective concludes that "this death occurred by murder, not natural causes" — a logical inference that "design-directed action did occur" can be scientifically justified.  How?  If we observe strong signs of design (as in a sequence of prime numbers, or in the circumstantial evidence for a murder) we can infer that design-directed action did occur, even if the agent and action were not observed.  Scientists can infer the existence of an unobservable cause (an electron, idea,...) from the observable effects it produces, in studies of current events or historical events.
    In some historical situations, only undirected natural process was involved, so a mechanistic explanatory theory is adequate.  In other historical situations, "what happened" was affected by the decisions and actions of an agent.  This introduces an element of unpredictability when making predictions, but this is acceptable because in a descriptive theory a historical scientist (in psychology, sociology, anthropology, archaeology, history, or forensics; or in geology, astronomy, biology, or paleontology) only has to determine what did occur, not predict what will occur.  And in an agency explanatory theory, proposing that "agent action was involved" is a scientific conclusion.

    Why is there controversy?  Design theories are common in science, and claims for design can be logically evaluated using the methods of science.  Therefore, why are there any doubts about whether a design theory can be scientific?  Why are most design theories judged on their scientific merit, while other design theories are excluded from science?  When examined carefully, methodological arguments for excluding design from science seem weak.  For most opponents of design, the main concerns are metaphysical, and a common claim is that a design theory is equivalent to a creation theory.  But design and creation are not the same, as explained below.
    In any area (radioastronomy, homicide, origins,...) an inquiry about design is a two-stage process:  first we ask "Was there design-directed action?", and then we investigate the details.  A basic design theory claims only that "design-directed action did occur" (the first stage) but does not try to explain the details (how, when, why, who,...) of design-and-production.  Of course, we should evaluate a design theory based on what it does claim (that design occurred) instead of what it does not claim (that it can explain the details).
    In origins, a design theory is not a creation theory.  A design theory can be supplemented with details (about the designer's identity and actions, about who, when, how, why,...) to form a variety of theories about supernatural creation (by God or...) or natural non-creation (as in a theory proposing that evolution on earth was intelligently designed and directed by space aliens who evolved before us).  A design theory — which does not propose divine action, but does acknowledge it as a possibility — does not try to distinguish between creation and non-creation.  Instead, a design theory just claims that "design-directed action did occur."
    A basic (non-supplemented) design theory is limited to claims that can be scientifically evaluated.  In a Response to Critics, Michael Behe explains: "Although I acknowledged [in "Darwin's Black Box"] that most people (including myself) will attribute the design to God — based in part on other, non-scientific judgments they have made — I did not claim that the biochemical evidence leads ineluctably to a conclusion about who the designer is.  In fact, I directly said that, from a scientific point of view, the question remains open.  In doing so I was not being coy, but only limiting my claims to what I think the evidence will support. ... The biochemical evidence strongly indicates design, but does not show who the designer was."

    Logic, Proof, and Future Science
  Logic requires that, during any intellectually rigorous attempt to explain the origin of an observed feature, scientists should consider all possibilities.  There are (at least) five possibilities:  Perhaps the feature was produced by undirected natural process and  1x) a current natural theory describes this process, or  1y) a future natural theory will describe the process, or  1z) no natural theory that seems plausible will ever be constructed because the process was too complex or unfamiliar or improbable for our minds to propose and accept.  Or maybe the feature was produced by  2A) natural design and construction, or  2B) supernatural design and creation.
    an application:  Current theories for a natural origin of life seem highly implausible.  Is it rational for scientists to consider the possibility that life might have been the result of design-directed action?  Of course, certainty is impossible because we can never propose and test all possibilities for non-design, so two non-design theories (1y and 1z) will always be possibilities.  But we could develop a logically justified confidence that our search has been thorough yet futile, and no promising approaches remain unexplored.
    Future developments in science could make the status of non-design increase (if we discover how a feature could have been produced by non-design) or decrease (if new knowledge reinforces our doubts about non-design).  To decide which "future science" is more probable, we must predict improvements in current theories and inventions of new theories.  For example, we can look at each reason that a natural origin of life seems implausible — due to properties like the unfavorable chemical equilibria for synthesizing biomolecules, and the high degree of biocomplexity required for metabolism and reproduction,... — and then try to imagine ways in which future knowledge might change our views of each property.  We can ask, "How likely is each change?" and "How would it affect our evaluations for a natural origin of life?"
    To make good predictions about future scientific developments, we need creativity (to imagine what could be) plus criticality (to make realistic predictions about what is probable in reality, not just possible in our imaginations) so we can avoid the extremes of insisting that in this area of science "nothing new will ever happen" or "anything could happen."  {an extreme scenario for denial: super-aliens from space}
    In the near future, scientists will disagree about the plausibility of design.  But this is not a cause for concern, because disagreement can be a healthy way to stimulate thinking and research by advocates for different points of view.

1) The disadvantages of Closed Science are described in the partner to this "brief intro to design" page, Methodological Naturalism in Our Search for Truth: A Brief Introduction.

3) Another page — Can a theory of design be scientific? — looks at questions (practical, methodological, metaphysical, trivial) and concludes that "arguments for excluding design from science seem weak" so "the closer we examine Open Science, the better it looks."

The adventures of Michael Behe (with scientific journals) illustrate the sociological challenges of Critical Thinking in Closed Science.

Why are theories of non-design (re: biological evolution) often considered to be more plausible than is scientifically justified?  This is explained in The Process of Logically Evaluating Origins Theories.

a design of nature?  Is a universe with natural process that is "just right for life" a result of design-directed action?  Anthropic Principle & Theology: Multiverse and/or Intelligent Design?

4) A larger page about methodological naturalism and intelligent design (and more) explains why Open Science is Better Science.

    The Origin of Life (by Chemical Evolution?) 
    Scientists who are trying to imagine how life might have arisen naturally propose a two-stage process:
    1) formation of organic molecules, which combine to make larger biomolecules,
    2) self-organization of these molecules into a living organism.

    What scientists are learning is that the complexity required for life (in terms of biomolecule formation and self-organization) is much greater than the complexity possible by natural process (beginning with lifeless matter).  This huge difference has motivated scientists to creatively construct new theories for reducing requirements and enhancing possibilities, but none of these ideas has progressed from speculation to plausibility.  {details}

    Perpetual Denial?  (What if design was proposed by space aliens?)
  Imagine a scientific community with trillions of super-intelligent space aliens (IQ = 20,000) each with a life span of a billion years, devoted to science (and using high-speed travel to explore a variety of environments throughout the universe) for the past 5 billion years, who have not yet constructed a plausible theory for a natural origin of life.  Even in this situation a denial of design would be possible, but would it be rational?
    In the near future, the actual state of human knowledge will remain much less advanced than this imaginary super-science, and critics of ID will point out, with some justification, the reasons for cautious humility when making claims for design.  But now we know much more about the origin of life than we did five decades ago, just after the original Miller-Urey experiments, and what we've learned makes a natural origin of life seem much less plausible.  At some point in our knowledge, it seems rational for scientists to ask, "Should we seriously consider the possibility that the first life was not produced by natural process?"  I think we've already reached the point where this question is rationally justified.

This website for Whole-Person Education has TWO KINDS OF LINKS:
an ITALICIZED LINK keeps you inside a page, moving you to another part of it, and
 a NON-ITALICIZED LINK opens another page.  Both keep everything inside this window, 
so your browser's BACK-button will always take you back to where you were.

Here are other related pages:

Read the page-reorganization described above:
"But my web-pages have been reorganized..."

Origins Questions (pages by Craig Rusbult)

Here are the pages in the original four-part series.
Part 1: Methodological Naturalism in Our Search for Truth
 Part 2: A Brief Introduction to Intelligent Design 
 Part 3: Can theories of design be scientific? 
 Part 4: Open Science is Better Science

Critical Thinking in Closed Science (Mike Behe,...)

The Process of Logically Evaluating Origins Theories

Anthropic Principle & Theology: Multiverse or Intelligent Design?

This page is

Copyright © 2003 by Craig Rusbult
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