I must say that I am a bit disappointed with this book. Its full title is "Believing: The neuroscience of fantasies, fears and convictions". And at the end of the prologue the author says that he was interested in studying what beliefs are, where they come from, how they relate to evidence, why they persist in the absence of evidence or in the presence of contradictory evidence and what the role of the brain is. Promising, right? So maybe naively, I expected answers to these questions. But the book turned out to be more philosophical in its discussion, and less "neuroscientific". The little of neuroscience discussed in the book is more in the line with what a common person will say. For example, a common person will say that someone did X because that was pleasing to him - directly or indirectly. The neuroscientists will say that action X causes activity in the pleasure centre of the brain that can be measured by an fMRI (probably the result of dopamine production) and that makes us feel good. Well, this latter explanation does not really advance our understanding of why this person did X more than the former explanation.

So how far down the causality chain did I expect the author to delve? Well this depends on what we consider as a satisfactory explanation. Do we need to get down to elementary particles? Not if an explanation at the molecular level suffices to explain how a process works and what we can do to change it. For example, if we know how the brain creates a feeling of pleasure (by secreting dopamine) and how dopamine production eventually stops (by dopamine inhibitors) and how hallucinatory drugs become addictive (by blocking the action of the dopamine inhibitors and thus cause the brain to be flooded with dopamine), then we can change the addiction by creating pharmaceuticals that either inhibit dopamine production or inhibit the action of the hallucinatory drugs on the inhibitors.

Part of the problem with this book is that the definition of a belief is too broad. The author does not restrict his inquiry into religious or ideological beliefs but extends it to cover even common day-to-day beliefs. For example, it is my belief that if I turn on the faucet, water will come out and further it is also my belief that if I drink the water my thirst, or that weird feeling I am having right now, will be gone. The author says that our brains have a bias in creating beliefs. Well thank God for that because if they did not we will have to start from scratch every time we wake up!

The author says that for some beliefs the distance between them and evidence is very small or non-existent (as will be the case after I turn on the faucet once), while for others it is very large, and that our brain has a tendency to eliminate this gap either by looking at the evidence or making it up! Again, not surprising. Of course our brain will try to close the gap because if it did not then someone could believe in something even though he also knew that what he believed in was either incorrect or unsupported by evidence?

Which brings us to evidence. Some evidence are easy to establish as the causal agents of something and are also easy to gather. For example, in the case of the faucet, I just need to do the experiment once to figure out the causality between turning the faucet and water running out. But what of other more complicated things: for example, I believe that my spouse loves me. So what do I need as evidence to close the gap between my belief and "reality"? Would taking a bullet for me be too much to ask? What about if she just said that she loves me? Clearly, then the "evidence" in this case are subjective and may vary substantially from person to person. So then what kind of evidence are they? And how useful is it to describe beliefs and distance from evidence?

In any case, I got to thinking that maybe I was being foolish to expect answers to questions that should not even be posed in the first place. For example, although we know a lot about dopamine production, it may not be very productive to ask "but why some actions, that do not involve the physical intake of a substance, cause dopamine production and others do not?" And there can be an infinite series of "whys" that could only have answers if molecules had goals and "objective functions", which they do not, other than the ones given to them by evolution. ( )