Harris argues that free will doesn't exist, a claim which, it seems to me, gets him entangled in a number snares, but I'll let Lawton explain:
Free will touches everything we value - law, politics, relationships, morality and more. And yet it is an illusion (according to Harris). We either live in a deterministic universe where the future is set, or an indeterminate one where thoughts and actions happen at random. Neither is compatible with free will.Yes, Harris chose to write the book, but the choice was determined for him, just as his belief in determinism was determined for him, by those dark prior causes. At least Harris himself must believe that, but that being so, why should anyone think that his belief in determinism is the product of rational reflection? Why should he think that the reader's rejection of his arguments has anything to do with the cogency of those arguments?
Having laid this out, Harris tries to salvage something from the wreckage. In the process he ends up rowing back to a position not unlike the "compatibilists" who argue that free will can be reconciled with the laws of physics, a notion he has earlier attacked.
Harris starts his rescue mission by pointing out that, even in the absence of free will, there is still a distinction between voluntary action and mere accidents. Imagine, he says, that while he is writing his book somebody outside fires up a leaf blower. He ignores the sound by attending to his work. The decision feels like the exercise of free will, but isn't.
Even so, the choice still matters because it leads to outcomes in the real world. "If I had not decided to write this book, it would not have written itself." His choice "was unquestionably the cause of it coming into being". But that choice came out of the "darkness of prior causes" that Harris has no control over. As he puts it: "You can do what you decide to do, but you cannot decide what you will decide to do."
To me that sounds like a bit of sophistry. Harris shatters the illusion of free will and tries to numb the pain with an argument that it is all OK because our actions have consequences. But even if we can make choices that make a difference, does that make them any more our own? Does that take us anywhere new? I'm not sure.
Regardless, Harris presses on to explain how this version of not having free will plays out in the real world. At the very least, his argument provides a refreshing antidote to the nihilism that the debate tends to produce.
What we choose to believe, if determinism is actually the case, is the result of a host of factors most of which we are unaware of and none of which have anything much to do with what's reasonable or true. The belief in determinism, if determinism is true, is simply the inevitable consequence of millions of chance events throughout our lives and even before our lives, as well as the genetic endowment we've inherited from a long skein of ancestors.
Indeed, in a deterministic world I'm not even sure what it means to talk of a "reasonable" belief. Reason is just another illusion like free will.
Given all this, I don't know how Harris can possibly avoid nihilism, as Lawton suggests he does, without taking an irrational leap, i.e. choosing to live as if he were free when, in fact, he knows that he's not. People who do this should not, however, pat themselves on the back for being exemplars of rational living.