rationalskepticism.org

ughaibu wrote:

scott1328 wrote:the statement “could have done otherwise” is semantically meaningless.

Of course it isn't. If at time one an agent can perform action A and distinct action B, then as A isn't B, if the agent performs B then they could have performed A. "Could" is just the past tense of "can".

scott1328 wrote:There is no possible world in which such world where such a statement could be verified. So ditching an incoherent definition is the only possibility.

Well, science requires that we can repeat procedures and it also requires controls, so there is more than one scientific procedure. This immediately entails that science requires that we can perform at least two distinct actions, and once we've performed one, that we could have performed a different one. In other words, science requires that we "could have done otherwise".
Now, what could anyone think is so important about denying the reality of free will, that they're prepared to throw out science in support of it?

The results of many thousands of scientific experiments indicate that our brains are determinate mechanisms, and as predictable in principle as any other mechanism. The results of science support the claim that we do not have ultimate free will.

However, although there is enough evidence to show that our brains are almost certainly determinate, we don’t yet understand the mechanisms, because they are very complex. Eventually, science may well be able to predict brains accurately and in detail, but so far, modern science is almost completely useless for predicting brains. In practice, we still predict each other using the prescientific evolved guesswork of Theory of Mind, which is better than nothing but not very accurate.

In the future, when brains are understood as mechanisms, social life may be very different, and the concept of free will may become entirely redundant. Changing people’s behaviour may well be a matter of changing brain structures, like tinkering with a car engine, or redesigning a robot. So far, we are nowhere near that stage, and social life includes a number of evolved behaviour patterns which we do not fully understand. Punishment and reward are used to modify behaviour, but they require coordinated group action, and we’re far from understanding exactly how this coordination comes about.

I think there is no inconsistency in claiming both that we are almost certainly determinate mechanisms with no ultimate free will, and also, at the same time, that while we do not understand those mechanisms it makes sense to continue using the concept of free will much as before. As you say, scientific methodology assumes that scientists have something like free will, but I certainly don’t agree with you that that shows science assumes we have ultimate free will, I think it shows only that scientists haven’t yet worked out the details of our brain mechanisms.