This is the weekly Q & A blog post by our Research Professor in Philosophy, Dr. William Lane Craig.
Dear Dr. Craig
I am a recent convert to Christianity, up until about 2 months ago I was a nihilistic atheist. Because of being an atheist most of my life, the majority of my friends are also atheist and are very eager to tell me how wrong I am about God using the writings of Hitchens, Dawkins, etc. It's because of you, Alvin Plantinga, Frank Turek, John Lennox, Ravi Zecharias and some C S Lewis that I've started to realize that Christianity might be true.
The problem my atheist friends bring up the most against me is they think logic and reason is due to chemical compositions in the brain. They always tell me how all we are are chemicals and electricity and everything is reducible to that.
My question is how can I show that reason and logic are not reducible to molecules and atoms?
I've gotten a bit snarky with them lately and I ask them things like "If reason is reducible to chemicals, I want you to stop proving things using science and logic (since they're products of atoms buzzing) and prove everything chemically and with brain tissue." Or "If everything is matter, then prove everything to me materially." They always answer back with "Way back in caveman times, do you think they would understand anything you're saying? That should show you how logic developed alongside the human brain!" Then I tell them if all we are are chemicals then we can't come to logical or scientific conclusions since molecules determine our thought patterns. I also tell them that science assumes logic is true, and that logic can never be found inside the universe or discovered since to discover logic in the brain as a molecule or as an atom or physical force in the universe using science, would mean that we would use logic to discover logic which is nonsensical. They then tell me to stop assuming logic is true and at that point I give up.
Is there anything fallacious with my propositions? How can I convince them to stop assuming materialism is true? Any help that you might give would be astounding.
Thank you for your time
Dr. William Lane Craig’s Response
I don’t think you need my help, Matthew! Your responses to your friends are dead on. I couldn’t help but smile at the self-referentially incoherent quagmire into which some nihilistic types work themselves. What is baffling is how blind such persons can be to their own incoherence.
If they think that logic and reason are unreliable because “logic and reason is due to chemical compositions in the brain,” then ask them, “How did you arrive at that conclusion?” If they used logic and reason, then their assertion defeats itself. If they did not, why believe what they say? These poor, deluded souls are mired in incoherence and don’t even realize it.
When they retort, “Way back in caveman times, do you think they would understand anything you're saying? That should show you how logic developed alongside the human brain!", you should explain that, of course, mathematics and logic have developed over time as people become smarter and more insightful. But that doesn’t imply that 2+2 did not equal 4 prior to people’s grasping this truth. Ask them if back in those caveman days, before people could grasp the idea of a planet, the Earth was round—or did the Earth become round with the development of science? They’re obviously confusing knowledge and reality.
When they tell you “to stop assuming logic is true,” the reductio ad absurdum is complete. You might ask them if they think that that statement is true rather than false, in which case they’re assuming the logical Law of Contradiction is true, or what inference they draw from that, in which case they’ll have to assume the logical rules of inference. But you may well be right that when someone is so mired in irrationality, it’s pointless to argue further. Here is where, perhaps, just being a loving friend is the best evangelism.