"There is no god...if every trace of any single religion died out and nothing were passed on, it would never be created exactly that way again. There might be some other nonsense in its place, but not that exact nonsense. If all science were wiped out, it would still be true and someone would find a way to figure it all out again."
Perhaps I should subtitle this post: "When bad logic attacks". Sometimes I wonder at someone who actually took the time to think this out and write it down and publish it--and yet never see the many flaws in his statements.
If Penn didn't spend any significant time thinking about it, I don't see why I should be any different. So here we go--the major logical and factual flaws in his argument, just off the top of my head:
Fallacy 1. Begging the question: his logic only holds if you assume the initial point ("there is no god") to be true. If there is no God, then he would be right--if religion were wiped out that particular religion would not regrow. But if God does exist, then of course that religion could regrow exactly as it was--for He could reveal it to them exactly the same way. So Penn's argument begs the question--it assumes its initial point to be true. Take away the initial point, and the argument falls apart.
Fallacy 2. Non sequitur: Penn is arguing that if (A) the religion could not regrow on its own to be exactly the same, then (B) God does not exist. In philosophical terms we say that the "it does not follow" (or, in Latin, non sequitur). The conclusion is not at all a requirement of the original statement. There is no reason that God could not create entirely different methods of worshipping Himself. In fact, some people believe exactly that--every religion is a "path" to the same God. (Of course that is rubbish, but it is at least logically coherent, unlike Penn's ramblings.)
Fallacy 3. Definition of science: Penn then goes on to say that science is "true". I don't think he understands what science is. Science is not a thing that can be true or false--it is a process of observing and experimenting to explain the world around us. It cannot be "true"; it is a process, not a thing. It is a nonsense statement--science is a process of discovering something which itself may be true or false. Because he fails to understand that science is not just some individual thing that is true or false, he also does not understand the reality of science--that at any given moment in history, the scientific community's beliefs about the world are filled with falsehood! Take the geocentric model of the universe, which every scientist believed. Ptolemy used real, and good, science in developing his model. Copernicus used good science in making his heliocentric model. Kepler used good science in adjusting the Copernican model to make it work. In each case, the "science" part was equally "scientific". But that didn't make the geocentric model true! If there is one thing we know for certain, it is that many of the things we believe to be scientifically accurate today are wrong, either due to bad experiments or bad assumptions or lack of data.
Fallacy 4. False dichotomy: Penn weirdly sets up the scientific method as the opposite of the existence of religion. Which makes no sense--the rise of science does not logically demand that a God not exist, nor does the existence of a God logically demand that science not exist. A great many scientists, in fact, happen to hold both views simultaneously--and their names read like a "Who's Who" of science history: Newton, Kepler, Euler, Descartes, Mendel, Kelvin, etc.
Fallacy 5. Appeal to probability: Penn assumes that "someone would find a way to figure [science] all out again". Again, due to #3, that statement makes no sense. I assume what he really means is, someone would one day reach our apparently-perfect (in his mind) modern understanding of nature again. Why? Just because something could happen does not mean that it would. Lots of aboriginal tribes have lived for millennia without the slightest interest in science. Why assume that science would grow without religion? (Indeed, Penn should study his history...very few scientific breakthroughs were made by atheists throughout our history. And without the monks of the Dark Ages copying the existing knowledge of the Greeks and Romans, the invention of the press by a Christian, the Protestant Reformation freeing access to all kinds of knowledge, and the works of Christian scientists like Newton, Copernicus, Kepler, etc., we would still be having tea in Europe and watching the sun revolve around us.)
If you had told me, "Hey, a Vegas magician who happens to also be a libertarian and an atheist is about to disprove Christianity in four sentences," I would have expected trite silliness. But Penn caught even me off guard here with the thoroughly juvenile logical processes from an otherwise seemingly clever man. Four sentences, which I read in less than a minute, and I see at least five major gaping flaws in his logic.
Penn has made logic disappear. He is a better magician than I originally gave him credit for.