A brief history of Intelligent design
ID has its roots in the modern ‘creation science’ movement pioneered in the 1960s by Henry M. Morris and his influential book, The Genesis Flood. During the 1970s and 1980s, creationist organisations vigorously promoted ‘young earth’ creationism – a commitment to a literal interpretation of the six days of creation recorded in Genesis.
In 1987, Edwards v. Aguillard ruled that the teaching of creation science in schools was unconstitutional, as it was a religious doctrine. Subsequently, the ID movement was launched, largely as a result of lawyer Phillip E. Johnson’s leadership and publication of Darwin on Trial. It eloquently repeated popular creationist criticisms of Darwinian evolution, and was critical of what Johnson perceived as science’s presumption of naturalism. Crucially, Johnson chose to avoid contentious issues such as interpreting Genesis and the age of the earth, and focused on a more fundamental issue – is life intelligently designed or the result of blind, natural causes? The main intellectual centre of ID quickly became the non-profit think tank The Discovery Institute.
Kitzmiller v. Dover Area School District was another significant trial in which demarcation was a central issue, this time concerning the teaching of ID in schools. Judge John E. Jones III used methodological naturalism as a key demarcation criterion, and concluded that ID was a religious argument, not science. Despite this setback, ID’s influence continued to grow, aided by the popularity of books such as Signature in the Cell (Meyer, 2009) and Darwin’s Doubt (Meyer, 2013).
What is Intelligent design?
The Discovery Institute defines ID as a theory holding ‘that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection’ (Discovery Institute, 2016a). Implicit in this definition is the assumption that this intelligent cause is not biologically related to and is ultimately responsible for the existence of all living things.
More specifically, the Discovery Institute states that ID ‘is based on observations of nature which the theory attempts to explain based on what we know about the cause and effect structure of the world and the patterns that generally indicate intelligent causes. Intelligent design is an inference from empirical evidence’ (Meyer, 2008). They explicitly state that ID ‘is a scientific theory that employs the methods commonly used by other historical sciences’ (Discovery Institute, 2016c).
There are two important points worth noting about these definitions. Firstly, they are non-religious, and the intelligent cause is not specified. Secondly, ID purports to be based on empirical evidence, and is explicitly claimed to be scientific.
The vast majority of ID literature concerns three main areas: specified complexity, irreducible complexity, and various anti-evolution arguments.
William Dembski’s The Design Inference (Dembski, 1998) attempted to place design arguments such as William Paley’s on a firmer footing by proposing a theoretical basis for detecting design. His ‘explanatory filter’ is a three-step procedure for deciding upon the best explanation for an observation (such as seeing Paley’s watch lying on a beach).
The filter first considers if a regularity (basically a deterministic consequence) is responsible for the observation. If this can be ruled out, chance is then considered, and if the probability of the observation being a chance occurrence is sufficiently low, design is concluded to be responsible. Dembski calls the probabilistic threshold for selecting design over chance the ‘universal probability bound’, calculating it to be 1 in 10150. This very large number is guesstimated as an upper bound on the number of physical events that could have occurred in the universe since the Big Bang. An observation classified as the result of design is said to have exhibited specified complexity, or complex specified information (CSI).
In more recent work (Dembski, 2005), the explanatory filter appears to have been largely discarded. Dembski collapses regularities and chance categories into one category, chance, and develops a formula for CSI, and a threshold for choosing design over chance.
The concept of ‘irreducible complexity’ (IC) is the claim that evolution is incapable of producing certain complex biological structures. An IC structure is one form of CSI. In the Origin, Darwin wrote ‘if it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down’ (Darwin, 1859, 189). Michael Behe applied this idea to biochemical systems.
According to Behe, a system is IC if it is ‘a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning’ (Behe, 1996, 39). Behe claims that such a system cannot have been produced by evolution, as its evolutionary precursor, missing one or more of the parts, would be non-functional.
Behe has proposed numerous biochemical systems as IC, including cell cilia, the bacterial flagellum, and the process of blood clotting.
Criticisms of evolutionary theory
ID’s criticisms of evolutionary theory are widely discussed in ID literature, and are also heavily promoted in the creation science movement – often as fatal flaws that threaten to demolish Darwinism. They include familiar arguments about the lack of intermediate fossils in the fossil record, the rapid appearance of complex lifeforms during the Cambrian explosion, the failure to produce a workable theory for abiogenesis, and cellular complexity.
Is ID creation science or religious?
The close links between creation science and ID have been well documented (Matzke, 2009). The Kitzmiller judgement ruled that ‘ID cannot uncouple itself from its creationist, and thus religious, antecedents’ (Kitzmiller v. Dover Area School District, 2005, 136), reasoning that the designer must be supernatural. This was a major factor in concluding ID was not a science.
This approach seems a dubious basis for demarcation. There are non-supernatural alternatives such as intelligent aliens, or that we are part of a post-human computer simulation. Historically, many sciences have disentangled themselves from questionable origins, and ID proponents have made considerable efforts to do so.
Phillip E. Johnson, in founding ID, made clear the differences between ID and creationism. Stephen Meyer states that ID ‘does not offer an interpretation of the book of Genesis, nor does it posit a theory about the length of the Biblical days of creation or even the age of the earth’ and ‘unlike creationism, is not based upon the Bible ‘ (Meyer, 2008).
Creation science organisations clearly state that science is subservient to Biblical authority (Creation Ministries International, 2015). This is not the case for the Discovery Institute, and ID’s definition has no religious references – it is ‘not a deduction from religious authority’ (Meyer, 2008). It is true that most of its proponents have a belief in some form of supernatural creator, but this is not a fatal objection – after all, most Renaissance scientists shared this belief.
In the interests of an impartial evaluation, ID will be assumed to be non-religious as claimed. Its scientific status will be evaluated on its current characteristics rather than its origins.