Irreducible Simplicity

As 20th-century scientific discoveries ostensibly challenged the foundations of religious belief, religious scientists stepped forward to respond. These responses vary widely in both rigor and cogency. Intelligent design arguments have been some of the most influential of these responses, first cropping up in the late 90s. Using the same assumptions and methods as the natural sciences, indeed using science itself, proponents of intelligent design provide a tenable response to scientific objections to religion. Two of its biggest advocates are biochemist Michael Behe (Darwin’s Black Box) and mathematician William Dembski (Intelligent Design). The work these thinkers have done has had an immense impact on the landscape of both academic dialogue and popular debates on science and religion. But, this style of argument limits itself to many of the same assumptions and methods as their secular counterparts, which is often missing key philosophical grounding. That philosophical grounding is key to overcoming the serious challenges that science has leveled against religion.

Metaphysics is ordered to finding the first source or the ultimate cause of all creation. For theists, that source is God. Share on XThe Five Ways, arguments on God’s existence written by St. Thomas Aquinas, proceed from the sound philosophical principles that underpin the natural sciences and are therefore much more effective. Though they were written over 800 years ago and they rely heavily on an Aristotelian framework from over 2,300 years ago, these arguments flow from bedrock metaphysical truths. Metaphysics is the study of being as being and so accounts not just for one particular category of empirical data (e.g., biology) but for being itself. By way of analogy, if the natural sciences study a house by looking at the wood, steel, and concrete that comprise it, metaphysics studies a building by looking at its blueprints. Metaphysics is ordered to finding the first source or the ultimate cause of all creation. For theists, that source is God. It is for this reason that St. Thomas calls metaphysics scientia divina, the divine science.

This article will propose that when arguing for the existence of God, the approach taken in St. Thomas’s Five Ways has significant advantages over the Intelligent Design approach. This becomes clear through a comparison of their starting points, methods, and conclusions.

Section 1: Comparing the Starting Points of Intelligent Design and St. Thomas

Beginning with Behe and Dembski, it’s important to note at the outset that their theories differ significantly. Behe bases his argument on biology and what he calls “irreducible complexity”. Dembski bases his argument on informational complexity and calls his position “irreducible specificity”. Still, they are certainly both supporters of science-based arguments for intelligent design. Both thinkers hold senior positions at the Discovery Institute which promotes research into and propagation of intelligent design arguments.

A major starting point shared by these thinkers is man’s ability to detect when something is intelligently designed or not. Behe says that if we observe a system with finely adjusted parts, all of which are necessary to the system’s function, then we have reason to think that a mind has designed that system. His classic example is the bacterial flagellum. This observation is in response to Darwin’s natural selection which many argue or suppose to be mindless. He reasons that the finely adjusted parts of the bacterial flagellum could not have evolved independently through a series of small, random mutations, if each on its own conveys no survival advantage.  The probability of all the parts arising from random mutations, being passed on through generations, and finally coming together into a functioning whole is argued to seem too low to be credible.  He argues that the only viable explanation of such a system is a mind, a designer.

Each of the Five Ways starts with some very general observation about the world, something everyone can know to be true from everyday experience without needing any kind of specialized experimental verification. Share on XDembski’s model and starting point are more mathematical, though it still draws upon biological principles in refutation of Darwinism. He uses “Complex Specified Information” (e.g., DNA) to ground his argument. He says that we see highly complex sequences of information in nature and then he tries to account for how those sequences come to be. His process involves crunching the numbers of probability for very specific sequences, like DNA. Like Behe, he points out that these informational sequences are only effective when they meet a very specific criteria. The criteria are so specific that they suggest a mind. If one small thing is out of place then the whole thing falls apart. Again, this starting point of informational sequences draws from the same well as the natural sciences. He is using empirical data delivered to us by the natural sciences and combines it with mathematics to draw out the idea that mindless natural selection is not capable of such specificity.

Reliance on specific scientific findings, however, means that this reasoning is susceptible to further scientific development.  For instance, consider the precursors to the parts of the bacterial flagellum. Initially they seemed to lack any survival advantage on their own. What would happen if it was later discovered that they actually did provide some unexpected survival advantage? This would greatly affect the probability that a series of mutations, filtered by natural selection, could result in the final structure. St. Thomas, on the other hand, certainly uses empirical data as a starting point in the Five Ways, but he is also using metaphysical principles to get at deeper truths. As already mentioned, metaphysics studies the truths that the natural sciences depend on to draw their conclusions–not the other way around–by examining being as such. This is a key difference between Dembski and Behe’s view and that of St. Thomas.

Another starting point that distinguishes St. Thomas from Dembski and Behe is that all knowledge begins in the senses. This separates St. Thomas from purely speculative thinkers and actually puts him in conversation with the natural sciences. Since he starts with empirical data in these arguments, as opposed to revelation or even purely speculative philosophy, he can actually bring his framework to bear on the same tangible data. For instance, in the First Way his first point is just that change happens. Empirically, it is hard to disagree. Each of the Five Ways starts with some very general observation about the world, something everyone can know to be true from everyday experience without needing any kind of specialized experimental verification. This is very different from the example of the bacterial flagellum, which would not be known or sufficiently understood without specialized equipment.

Another key starting point for St. Thomas is what contemporary philosophers call the Principle of Sufficient Reason. It is a confidence that for any existing state of affairs, there exists something that sufficiently explains it. For instance, if we start with the observation that there is motion in the world, there must be some explanation or cause of that motion. This principle is what undergirds scientific inquiry. Each of the Five Ways begins with a very general observation of the state of affairs of the world, and then reflects philosophically on what must be the case to explain this state of affairs.

This brings us to the last starting point for St. Thomas, which is the wide range of modes of explanation he may draw upon. Where Dembski and Behe would consider causation mostly as efficient causality (e.g., a builder causes a house to exist by physically constructing it), St. Thomas draws on a much broader sense of causation which he picks up from Aristotle. The four causes are the material cause (i.e., the wood that the builder uses to make the house), the formal cause (i.e., the plan or idea in the mind of the builder which he’s trying to execute), the efficient cause (i.e., the actual constructing of the house), and the final cause (i.e., the purpose or function of the house). So there isn’t just one cause, but all these are causes of the house. It’s true that we don’t normally speak that way, but Thomists from Protestant traditions like E.L. Mascall, Austin Farrer, and more recently John Millbank, have done great work in bringing Aristotelian and Thomistic metaphysics back, at least into academic conversations.  St. Thomas’s Aristotelian framework is the main barrier to entry for these arguments.

Section 2: Comparing the Methods of Reasoning 

The Five Ways of St. Thomas also differ from Intelligent Design arguments in how exactly the arguments proceed from their starting points to their conclusions.  The different ways of proceeding carry with them different degrees of certainty. Intelligent Design arguments are inferences to the best explanation. Starting with scientific observations, such as how the parts of a bacterium’s flagellum work together and the irreducible complexity of this system, Intelligent Design proponents argue that the best, most probable explanation for the observations is intelligence. A very high probability leads to high confidence that the best explanation is correct. However, it is always possible that the probabilities are not quite what we thought, and so, the degree of certainty of the conclusion is itself uncertain.

In contrast, the method of reasoning at work in St. Thomas’s Five Ways is syllogistic deduction.  St. Thomas does not argue that the most likely explanation of motion or contingency or ordered inclinations in the universe is an Unmoved Mover or Necessary Being or Intelligent Orderer.  Rather, he offers the existence of the Unmoved Mover, etc., as the necessary and certain conclusions that follow from his premises.  That is to say, the general observations about the world that serve as the starting points for the Five Ways simply would not make sense and are not, even in principle, possible without the existence of the Unmoved Mover, etc.  In a valid syllogism, the conclusion follows from the premises without fail.  This means that the Five Ways stand or fall entirely on the truth of the premises, and especially the Aristotelian framework used in the premises.

Section 3: Comparing the Conclusions

Perhaps the starkest difference between the Five Ways of St. Thomas and Intelligent Design arguments is in their conclusions. In staying close to scientific methodologies, Intelligent Design arguments have a modest goal: to argue merely that some kind of intelligence is in some way involved in designing how certain observed biological realities came to be. These do not go further to attempt to say how the intelligence is involved or to claim to know much about the intelligence. They are not able to argue from their data that the intelligence involved is infinite or omnipotent or that the same intelligence is involved in every instance of design. Accordingly, Intelligent Design proponents admit that the intelligence involved is not necessarily God.

St. Thomas argues that the Five Ways terminate in the Being that has all the divine attributes of classical theism. Share on XIn contrast, St. Thomas sets his sights much higher.  At first, the conclusions of each of the Five Ways may not appear impressive or informative, e.g. there exists an Unmoved Mover, but St. Thomas does not stop there.  He goes on in the following pages of the Summa Theologiae to argue that what is shown to exist in the Five Ways is subsistent Being Itself, which he further deduces must be immaterial, transcendent, unlimited in power, lacking no perfections, metaphysically simple, and eternal.  In short, St. Thomas argues that the Five Ways terminate in the Being that has all the divine attributes of classical theism.  St. Thomas is not exaggerating when he ends each of the Five Ways by saying that this Being that must exist is “what everyone calls God.”

Conclusion

Although we are not able to explain in a single article everything needed to evaluate the strength of either the Five Ways or Intelligent Design arguments, we have at least sketched an outline of the reasons why no one should confuse the Five Ways with Intelligent Design arguments or hastily lump them together as the same sort of argument.  While Intelligent Design arguments are focused on very specific observations gleaned from scientific biological investigation, the Five Ways begin with very general observations that everyone knows to be true from everyday experience.  While Intelligent Design arguments make an inference that intelligent design is the most probable explanation for some specific biological systems, the Five Ways proceeds by deduction from general features of the world and an Aristotelian metaphysical framework to conclude that God must exist.  Finally, while Intelligent Design arguments conclude that some kind of intelligence, which may or may not be God, is responsible for these specific biological systems, the Five Ways conclude that the all-powerful, perfect, and eternal God of classical theism must be responsible for the world at large.  Given these advantages, the Five Ways should garner at least as much attention as Intelligent Design arguments.

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