Excellent book.

The topic comes up in Pirsig's Zen and the Art book where, in the context of Native American ancestor worship, Pirsig compare such things as our laws of physics to 'ghosts' that still have a real effect on people:

‘Oh, the laws of physics and of logic . . . the number system . . . the principle of algebraic substitution. These are ghosts. We just believe in them so thoroughly they seem real.’

@Matias oh well. I was thinking "this book would be right up his alley". you beat me to it!! I really enjoyed that book. It's been so useful.

@brentan Personally I think Pirsig is a bit off on saying that because we believe in these 'ghosts' so thoroughly they seem real.

Math, logic, laws of physics- they are very useful tools that have helped us understand natural phenomena around us, helped us understand how they relate to one another, and to bend them to our desires. We've been able to shape reality around us in some very awesome ways because we conceived of these ideas. Sure, they are "ghosts" because they don't live in a physical sense, but they weren't supposed to be. It's not that simply believing in them makes them real. Because they are ideas, their existence in reality in a physical sense is not even a useful quandary.

Am I off the mark there?

@Rooster128 No, you’re not off the mark. You’re being very perceptive. I think the conversation he said these things in might help explain them. His son Chris has said his Native American friend believes in ghosts:

‘Tom White Bear said his mother and dad told him not to believe all that stuff. But he said his grandmother whispered it was true anyway, so he believes it.’ He looks at me pleadingly. He really does want to know things sometimes. Being facetious is not being a very good father. ‘Sure,’ I say, reversing myself, ‘I believe in ghosts too.’ Now John and Sylvia look at me peculiarly. I see I’m not going to get out of this one easily and brace myself for a long explanation. ‘It’s completely natural,’ I say, ‘to think of Europeans who believed in ghosts or Indians who believed in ghosts as ignorant. The scientific point of view has wiped out every other view to a point where they all seem primitive, so that if a person today talks about ghosts or spirits he is considered ignorant or maybe nutty. It’s just all but completely impossible to imagine a world where ghosts can actually exist.’ John nods affirmatively and I continue.
‘My own opinion is that the intellect of modern man isn’t that superior. IQs aren’t that much different. Those Indians and medieval men were just as intelligent as we are, but the context in which they thought was completely different. Within that context of thought, ghosts and spirits are quite as real as atoms, particles, photons and quants are to a modern man. In that sense I believe in ghosts. Modern man has his ghosts and spirits too, you know'.

Pirsig doesn’t specifically say this but I think he means the ideas passed down by tradition to Native American tribes come from the ghosts of their ancestors. Those ideas are now obsolete as indeed our more recent ideas on physics are being challenged and changed as time moves on. That’s the best I can make of it.