Why Darwin Matters_ The Case Against Intelligent Design - Michael Shermer [25]
Investigating Intelligent Design
Skepticism—thoughtful inquiry—is a scientific way of thinking; science—a testable body of knowledge—is applied skepticism. At the core of any scientific investigation are a number of skeptical principles that help us assess the validity of a claim before we examine the specific arguments and evidences. Six principles of skepticism help us sort through the various arguments for Intelligent Design:
Hume’s Maxim, or, what is more likely?
In 1758 the Scottish philosopher David Hume published his most influential work, An Enquiry Concerning Human Understanding. When confronted by the claim of an event so improbable and extraordinary that it is called a miracle, Hume asks us to inquire what is more likely: that a supernatural act occurred contrary to the laws of nature, or that people who describe such acts are mistaken in their assessment of the event’s supernatural nature? Hume’s Maxim is best defined in his own words: “The plain consequence is (and it is a general maxim worthy of our attention), ‘That no testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous than the fact which it endeavours to establish.’ ”
Hume then weighs which is more likely: “When anyone tells me that he saw a dead man restored to life, I immediately consider with myself whether it be more probable, that this person should either deceive or be deceived, or that the fact, which he relates, should really have happened. I weigh the one miracle against the other; and according to the superiority, which I discover, I pronounce my decision, and always reject the greater miracle. If the falsehood of his testimony would be more miraculous than the event which he relates; then, and not till then, can he pretend to command my belief or opinion.”3
The evolution–Intelligent Design debate boils down to a Humean question of what’s more likely: that the diversity and complexity of life we see around us came about by laws of nature that we can observe, or supernaturally by an Intelligent Designer that we cannot observe? The nineteenth-century social Darwinist Herbert Spencer answered the question rhetorically: “Well, which is the most rational theory about these ten millions of species? Is it most likely that there have been ten millions of special creations? or is it most likely that, by continual modifications due to change of circumstances, ten millions of varieties have been produced, as varieties are being produced still?”4 It’s a good question.
The Known and the Unknown, or, before you say something is out of this world, first make sure it is not in this world.
Creationists and Intelligent Design theorists explain natural phenomena by turning immediately to supernatural forces operating outside this world. Following that thinking, there is no point in searching for medical cures in the natural world; we should throw out all medical knowledge and turn purely to prayer, without trying any treatments. But medicine, like evolution and other sciences, deals with natural explanations for natural phenomena, and even with only a rudimentary understanding of the natural world we should seek answers from the known, natural world first. Before assuming that the unknown is the only possible way to account for the complexity and diversity of life, it must first be demonstrated that known forces and processes cannot do the job.
Burden of Proof, or, extraordinary claims require extraordinary evidence.
Darwin’s original claim of evolution by means of natural selection was an extraordinary claim in its time, so he was required to provide extraordinary evidence for it. He did, and evidence has continued accumulating ever since. Today, the burden of proof is on creationists and Intelligent Design advocates to provide extraordinary evidence for their extraordinary claim that a supernatural