This review is mostly intended to address a common, and I think fair, criticism of The Will to Believe, that being his tendency to make it easy to allow people to believe, in areas of religious metaphysics (and this is an important line to draw), whatever they want. My take is based on a couple of readings of both The Will to Believe, and James' Essays in Radical Empiricism, and is therefore not laborious or scholarly. It is simply my impression as a reader.
The first part of this impression is that James was simply not addressing the right audience for the above criticism to hold much weight. He was lecturing to the philosophy club at a university well known for its theology program; or he was lecturing to the Young Men's Christian Association; or he was speaking to a number of Unitarian ministers. In most cases, his lectures were aimed at those who either already believed in God, or who might want to believe in God if he hasn't been killed by Reason. James repeatedly admits that most of his arguments are negative--that is, they don't provide evidence *for* God (or religion in general), they're meant simply to show that such belief is not necessarily negated philosophically, that there's *room* for religious belief.
Also, in order to understand James' approach, one has to remember that he was a psychologist ("Father of American psychology", in fact) and keep in mind his radical empiricist philosophy and its most obvious consequent, pragmatism. To James, there could be no absolute standard for "proving" or "refuting" such metaphysical ideas as religion is based around. Truth, according to the theory of pragmatism, is defined in terms of the idea's consequences, how well employing an idea fulfills what we want to get out of it (to simplify quite a lot). James certainly didn't think all beliefs were created equal; the proposition "boiling an egg makes cats rain from the sky" is verifiably false by any empirical standards, especially pragmatic ones. It's just that religious consequences are either currently or permanently not subject to any form of empirical testing. Those familiar with Alfred Korzybski's work should know what I mean very well.
James' arguments following this point are made as a genuine psychologist, focusing not on telling us what we should or shouldn't be believing and what grounds we should make them on (note the "shoulds"). His focus is on how people *will* actually make these kinds of decisions, what the actual conditions of people's belief are. As someone studying social and cognitive psychology right now, I can say that James' work is still relevant and insightful in this area. His conclusions were that most people are going to believe what meets their goals, and that this largely consists of feeling comfortable--for some, even the use of rigorous logic has no other purpose.
But it is also true that James never went as far as he could with his reasoning. He was content to help Christians stay Christian, and focus on using his ridiculously keen mind to make room for religion.
There is, however, a converse side to this that few people notice. He allows people to stay comfortable with their beliefs, but this should also point out that *those* wackos over there are believing their religion on exactly the same foundation as you. He allows you to believe whatever you want, but he also allows you to believe whatever you *don't* want. His philosophy taken to extremes could even undermine the view that any belief is entirely rational. If James had gone farther than his own comfort zone with his philosophy, he could have been a Zen master or a Dionysian figure to rival Nietzsche.
I suggest that questions of which beliefs are "True", and whether you should change yours or not, should be categorically divorced from the scope of this book. My impression is that James was not trying to answer these questions, and that a criticism based on his failure to do so doesn't make sense. This work is epistemological method, not metaphysical conclusion.
My point is ultimately that there's more in James' work than what he himself does with it. His essay on Hegel's philosophy shows an understanding of what Gregory Bateson would call "logical levels" several decades after James' death. His approach to philosophy, ethics, and religion was one of personal responsibility and a purposeful orientation. He's not going to tell you what to believe or what not to believe, except perhaps that you may as well pick whichever beliefs you get the most out of (note that this attitude does not exclude, or even discourage, rational, reasoned decision making). For this, my respect for James increases, as he understood that on a certain epistemological basis, there is no grounds for mandating "Truths" that can never have any solid empirical basis--the world has had enough people doing that, and we don't really need more.