Causal determinism is not a threat to freewill.
Quote:Causal (or
nomological) determinism is the thesis that future events are necessitated by past and present events combined with the laws of nature. Such determinism is sometimes illustrated by the
thought experiment of
Laplace's demon. Imagine an entity that knows all facts about the past and the present, and knows all natural laws that govern the universe. Such an entity might be able to use this knowledge to foresee the future, down to the smallest detail.
The key word in the above paragraph is "necessitated". It's this term that gives the argument its weight. It's also this term that is decidedly unscientific. There's no possible way to test if an event is necessary i.e. it
has to happen. You could flip a coin once a second and have it land on heads for the next 1,000 years but you still wouldn't have observed anything
necessary. There's no possible way to test between something that
has to happen vs.
just does happen. In all cases we can only observe what
happens. Even if something always happens that doesn't therefore mean that it
must happen.
If the following statement is true...
1. You will wear a yellow shirt tomorrow.
...then it is true only because, tomorrow, you, in fact, wear a yellow shirt.
Likewise, if the following statement is true...
2. Nothing accelerates faster than the speed of light.
...then it is true only because, at all times and places, nothing, in fact, ever accelerates faster than the speed of light.
Statements take their truth from the world. The statement "the cat is on the mat" is true iff the cat is on the mat.
Though, some people have it curiously twisted. They think that, in fact, nothing accelerates faster than the speed of light
because the statement "nothing accelerates faster than the speed of light" is true! Instead of the statement being true because it corresponds with reality, reality conforms itself to the truth of the statement. That sounds much like the way chanting a magic spell such as "open sesame" can make the world conform to its power.
At this point, most people would say...
"But if it's true that nothing accelerates faster than the speed of light then I
can't accelerate faster than the speed of light!"
This is a retreat to logical determinism and this is also a form of the modal fallacy. Strictly speaking, it's not that you can't. It's that you
won't. Let's go back to a mundane example. If it's true now that..
3. Tomorrow I will wear a yellow shirt.
...then it seems like I have no choice but to wear a yellow shirt. I can't change my mind. That's false though. The solution to the problem is that (3) is only true because I don't change my mind. If I do change my mind then (3) won't be true. By saying (3) is true we're also implying "I will change my mind and wear blue instead" is false.
If we take this further and make it a law-like statement...
4. Night Ripper only wears yellow shirts.
...then (4) is true only if I never decide to wear a different color of shirt. If one day I decide to wear blue then (4) is false. However, we're already taking (4) as true now. Therefore, I
don't (not that I
can't) ever change my mind.
The universe isn't governed in the sense that the universe has to behave a certain way. It's rather that the universe can be described with law-like statements. The truth of these statements don't thereby
force us into doing anything, however.