To which I would (and did) respond that we act as if we have free will because we have no choice. What would it look like to act "as if" we don't have free will? I would contend that it's simply not possible to do so. Whatever actions we take, they are taken on the basis of something we call decision-making. Even if we say that we are going to decide something on a purely random basis, that in itself is a decision (as is the choice of what means of randomisation we're going to use).
Far from being an abrogation of the naturalistic viewpoint, acting "as if" we have free will is an acceptance of the naturalist position. Here's what I posted in the discussion:
Last Saturday's Unbelievable? was about RE in schools, and the supposedly hidden agenda claimed by Mark Roques (Justin Brierley's other guest) that there's an underlying bias towards consumerism. Andrew stated that in his visits to schools he'd not found this. His own familiarity with RE teaching comes from his personal educational experience and his involvement as Education and Outreach Officer of the British Humanist Association, before he became BHA Chief Executive.
This is an interesting thread, but there seems to be a real confusion derived from the presupposition that dualism is true. One can't prove that the mind affects the brain by assuming that the brain and the mind are fundamentally different but nevertheless physically real things. As far as I'm aware this has not been shown. The mind is a manifestation of our perception of the brain's effects, and arises wholly from or through the brain. It's a one-way process — brain causes mind. Mind does not cause brain (or brain-chemistry), any more than an oil-painting causes brush-strokes on canvas, or than a tasty meal causes its ingredients. The meal may have a description (a recipe or even a menu) but the taste of it is not caused by the recipe.
What we perceive as "mind" is likely a combination of codified perceptions that manifest as patterns within the brain, but that cannot exist separate from the brain. (Fergus quotes neurologist Steve Novella, who is pretty clear on this matter.)
I would take issue with the contention that the mind can causally affect the brain. Attributing causal effects like this seems (as I said above) to be presupposing dualism. If the "mind" is simply what the "brain" does, then at bottom they are the same thing. What we call mind is no more than the product of the brain — so in this sense the brain could be said to cause the mind, but not vice versa.
Also the idea that "free will" is something humans (or indeed "moral agents") have and animals don't is problematic. It places free will as a specific attribute, like colour vision, rather than the emergent property that it most likely is. One might also say that the existence or not of free will is on a par with the existence or not of the soul, both of which I see as properties of cognition — handy short-cuts to understanding the world we live in, but not necessarily truly existing in themselves.
As for whether it's illegitimate to act "as if" we have free will if in fact we don't — we do this because we have no choice. It's not possible for anyone to act "as if" they don't have free will, because that very decision is — or appears to be — an act of free will. It is therefore quite possible that free will is an illusion, and that determinism is true. The question then becomes, determined by what?
Mark's stories seemed to me to be a little contrived, and perhaps even condescending in the faux accents with which he delivered them. Maybe they'd go down well with a particular audience, but I found them mildly irritating.
Andrew maintains that humanism should be taught in RE, as should any system of beliefs, worldview, ethics, etc., and that RE is doubly misnamed — we don't have Historical Education or Geographical Education, and RE lessons should include non-religious viewpoints.
It was a very civilised discussion, and started to liven up at about 43 minutes in, when Mark challenged Andrew's basis for making reasoned statements (a lot of theists take this tack, whether it's grounding for reason, logic, morality or truth — presuppositionalists especially love this argument). But Andrew Copson has dealt with this kind of thing before, and he answered concisely: "Reason is clearly a product of human interaction with reality." He went on to say, "Logic is the word that human beings have chosen to give to certain processes of reasoning. It has no objective existence. It's a process that we've come up with and that we apply, to discover certain truths..." And he followed this up with an excellent explanation of autonomy (which is what the thread on the discussion forum is about).
Mark Roques' general demeanour seemed to be one of I'm telling you stuff you've not heard before, and you're going to find it surprising. Andrew, of course, has heard it before. Mark also appeared to be on the back foot when he resorted to a variation of Some of my best friends are humanists....
In response to Mark's main thesis Andrew stated that he could not "see any logical connection between philosophical materialism and consumerist materialism." This is, however, what Christians and other religionists often attempt to imply, thereby claiming that the materialist position is nihilistic.
This was a good Unbelievable? — as are all that have Andrew Copson as a guest. As far as I can gather this was his sixth appearance, and all but his first are available for listening in the Unbelievable? podcast archives.
An mp3 of last Saturday's show can be downloaded here: