Nathaniel asked:

I have a question, I’m starting to believe in determinism. but I see one small problem. say a man goes into a coma, awakes with the knowledge to speak but has no prior memory of his past (subconscious or conscious). the nurse asks him if he wants outcome 1 or 2. he has no memory of either outcomes and therefore no predetermined subconscious decision could be made. What would be the reasoning behind his choice? Please assume he cannot ask information about the two outcomes before he makes his choice as I believe his first choice would be to ask about them because he has no belief, desire, or temperament in this situation. I know this is a hypothetical situation and might be a little silly, but I believe this question to be the only one I could ask.

Answer by Geoffrey Klempner

This is a great question, Nathaniel. Don’t worry if you’ve tried on a few people and they thought it was silly, because it isn’t. It is anything but. If we can’t solve this then determinism as applied to human behaviour is a dead duck.

Suppose the man chooses 1. Why 1? What is so special or pertinent about 1 that makes it preferable to 2? Or suppose he chooses 2. Why 2? What is so special or pertinent about 2 that makes it preferable to 1?

— Actually, I think this could be a slight worry about your example. Surely, a person can have a general preference for odd numbers over even numbers or vice versa. (The Pythagoreans saw the odd and the even as having fundamentally different cosmic attributes.) The same worry would in principle apply to any two numbers. What you want is a way of referring two two options that is completely neutral.

And that’s difficult. In principle. Press the button on the left or the right? No good. Go through the door in front or the door behind? No good. Think up any method you like, there will always be some difference that, even if it isn’t relevant to the outcome of the decision, is still sufficient for making a determined choice.

The medieval logician Buridan was here first. He proposed the scenario of a hungry ass placed at an equal distance between two baskets of food. There has to be some basis for choice, otherwise the ass will die of hunger.

Except we know it won’t. There is no way of setting up the experiment that will result in a dead ass — leaving aside moral considerations. However (as I seem to remember from an answer I gave quite a while ago) you can do this with a house fly. Say, you are squeamish about killing flies but don’t like them flying around your kitchen and nibbling at your food. You can literally catch a fly with two wads of soft cotton wool. Wave the wads slightly as you approach slowly from the left and the right at the same time. The fly will try to turn. Follow it. Then close in. Carefully transport the fly inside the cotton wads to an open window and let it go.

You might need to practice a few times. There will be some fly deaths. But eventually, you’ll get there.

Why can’t you do this with an ass? Aside from he size, because the ass has a more sophisticated nervous system. When faced with the two basket scenario the ass does a little thing in its head equivalent to tossing a coin. It just chooses, for no reason.

When chess playing programs were first devised, the programmers faced a similar problem. The program will sometimes evaluate two possible outcomes as exactly the same, say, one quarter of a pawn. In that case, in order to move, the program has to make a random choice.

And that’s what we do. A lot. Think of supermarket isles with long lines of cans of beans, or TV controllers with rows of buttons. If we weren’t able to make these kinds of choices, the human race would have died out long ago.