Thursday, October 24, 2013

Are we free to change the past?

Let P be a complete description of the ancient past and let L be the laws. Lewis agrees that our freedom includes the ability to act in a way that falsifies the conjunction P&L but denies that it includes the ability to act in such a way that were we to act so, P would be false.

But here is a plausible thesis. Fundamental particles are essentially tied to laws of nature. There would be no electrons or photons if the laws of electrodynamics were different. This is clear on the Aristotelian picture on which laws are grounded in the powers of objects, but is also plausible without that picture.

Given this plausible thesis, P entails L. And hence P&L is logically equivalent to P. Thus if we can act in a way that falsifies the conjunction P&L, we can act in a way that falsifies P. Lewis denies the thesis, but it is still plausible.


Mike Almeida said...

I think this is easier. There are facts about the past that change when we get a minor miracle in "violation" of actual law L. We have it true in the entire past that L is not a law. That is a fact about the past that, in some sense, we are free to modify.

Alexander R Pruss said...

Yeah, but it's the ancient past that Lewis says we can't affect.

William said...

Can a "complete description" of the past change while the described ancient past itself remains the same?

For example, can there be two different descriptions of that past that differ somehow based on two different future points of view?

Mike Almeida said...

Alex, you will have changed the ancient past. It will have ben true from the first moment of the universe that L (the actual law) is not a law of nature. Can't get more ancient than that.

Dagmara Lizlovs said...

"Are we free to change the past?"

According to my favorite intellectual of all time, Stephen King, in his monumental philosophical treatise: "The Langoliers" - "NO!"

This comes after being out all day bundling grass for goose blinds with my hunting buddies. Opening day three short weeks away! :-)