The Greatest Show on Earth - Chapter 1

Summary of Chapter 1: Only a Theory?

• Dawkins asks us to imagine we are a teacher of Roman history but you were distracted by "ignoramuses" who denied Romans ever exists.  You were demanded to "teach the controversy" ... how frustrating
•  Things like this really happen, as is the case with Holocaust-deniers
• Science teachers today face similar opposition w.r.t. teaching evolution
•  Many religious leaders accept evolution and don't find that it conflicts with their faith. 
•  Dawkins doesn't intend this as an anti-religious book, only a book that defends the evidence for evolution (he's ripped religion to shreds in other books, no reason to do it again here)
• However, religious leaders accepting evolution doesn't seem to transfer to their congregations ... 40% of Americans deny that humans evolved, and instead were created by God in the last 10,000 years.  He refers to this group as "history deniers", or "40 percenters"
• Perhaps this is true because clergy talk a lot in symbolism, and don't make it clear what's symbolic and what's literal.  How is the congregation supposed to know the difference?
• Evolution is a fact beyond reasonable, serious, sane, intelligent doubt
•  "No reputable scientist disputes it, and no unbiased reader will close the book doubting it"
• Next, Dawkins spends time discussing the definition of a "theory", and why there is so much confusion around it, especially since people of faith love to apply the label "only a theory" to evolution
• The definition of theory has 2 meanings 1) A set of ideas that explains a group of facts; a hypothesis confirmed by observation or experiment, etc. OR 2) A hypothesis, speculation, conjecture, etc.
•  He thinks scientists mean Sense 1 and creationists "mischievously" mean Sense 2
• Evolution is a theory in the same sense as the theory that the Earth orbits the Sun (heliocentric theory)
• He then discusses whether evolution has been or can be 'proved'.  He discusses what it means to prove something.  By a certain philosophy, only mathematicians can ever prove anything, such as the Pythagorean Theorem.  By this view, scientists can never prove anything.
• However, scientists can accumulate so much evidence for a theory that continuing to deny it a fact becomes ridiculous
• When theories are beyond sensible doubt, we call them 'facts'
•  Even labeling something a 'fact' does not have the same rigorous status as a mathematical proof
• He discusses the definition of a 'fact', and points out that even things we think are facts are not always reliable, such as the case with false-convictions based on eye-witness testimony
• Evolution happens too slowly for eye-witness testimony, so scientists must use inference
• "This book will take inference seriously - not mere inference but proper scientific inference"
•  Example of inference: Understanding continental drift, we can infer that South America was once joined to Africa
• Evolution is both fact and theory ... all living things are cousins is a fact, the process that drives it, natural selection, is a theory (Sense 1 theory, not Sense 2)
• In Darwin's day, evolution was more conjectural, but now we have compelling evidence that it is true
•  "Nowadays it is no longer possible to dispute the fact of evolution itself"
• All reputable biologists agree that natural selection is one of the most important driving forces
• Because we cannot directly observe evolution, we will examine the case for evolution much the way a detective examines a crime scene

Kevin's Commentary on Chapter 1

I have personally engaged in conversations and debates with people of faith, namely Christians, that attack or dismiss evolution as "only a theory."  Therefore, I find Dawkins lengthy discussion of theories, hypotheses, facts, and proofs both useful and relevant to my experience.

I watched a YouTube video with Kenneth Miller not long ago, and I thought his explanations of theories vs. facts was as good, if not even better than Dawkin's treatment.  Miller said that people generally think that facts are things that scientists are sure of, and theories are things we're not so sure of.  But, he explains, theories are actually more powerful than facts because theories explain facts.  I love that explanation.  Dawkins says nearly the exact same thing when he quotes the dictionary definition of theory.

Evolution by natural selection is an elegant, powerful theory that explains an enormous variety of facts we've collected, such as the fossil evidence facts, the facts about cells and DNA, the fact that life is so diverse and different around the world, and the facts about the behaviors of different forms of life.  Labeling evolution as a "theory" does not drag it down into the depths of doubt, but rather, lifts it up to a higher place in the world of science.

The creation hypothesis, on the other hand, does a terrible job of explaining the facts of the world around us (more on this in future chapters).  The contrast between these two world views I find very compelling.