In defence of this bold claim Boghossian puts forward a central big idea: to get sensible beliefs you need to use reliable ways of knowing. Peter illustrates this using an instance from his life where he needed to work out the size of a broken door in his house. He suggests that if you want to know this reliably then you shouldn’t ask your dog, shouldn’t use divination and you shouldn’t offer a goat as a sacrifice. Instead, you should use a tape measure. And fair enough. You won’t be surprised to hear that, in my part-time job as a surveyor, tapes are my go-to device for finding out the size of doors.

The general idea aside, this illustration is not great. It doesn’t recognise the complexities of knowing in real life. So sometimes asking dogs can be a good way to find things out. My dog loves tennis balls, and her sense of smell is so acute that she can find them in closed cupboards or under beds. She knows the words “find” and “ball” and will do so on command. She is the most reliable method I have for knowing where hidden tennis balls are! More to the point, however, I don’t know anyone who actually tries to measure distance using dogs or divination. Similarly, my hunch is that goat sacrifice isn’t about finding out things at all – it’s more likely to be about appeasement. Nevertheless, despite the weakness of the illustration, Boghossian’s key idea is well made. We should know using reliable methods. Where he goes wrong, however, is to then go on to say that the only reliable way of knowing things is via the scientific method. In other words the only beliefs that are sensible are ones based on reasoning from objective evidence – ideally in laboratory conditions.

Now I agree that reasoning from objective evidence is a very good way of knowing lots of things. Especially scientific things like door sizes. But just a little reflection reveals that it is not the only way we know things. In everyday life we know things through a whole range of different methods. We know some things, like the fact that child abuse is wrong, intuitively. We know some things, like I have a headache, from personal experience. We can know some things, like riding a bike, through just doing it. And we know some things – and probably most things – through other people telling us. So, aside from a few monuments, everything we know about the past is based on eyewitness testimony. Similarly, most of what we know of our friends is from their personal testimonies. In fact, a few experts aside, pretty much all we know about science comes from what our teachers tell us.

The upshot of this is that reasoning from objective evidence is well and good. But it really doesn’t give us enough knowledge about so many important things in life like other people, morality, experiences and history. We know these things in so many other ways that are also well and good, ordinary and necessary.
Here’s an example. An ancestor of mine was one of the earliest European settlers in the Canberra area. Near the end of his life he produced an oral history of those early years. It’s a great read, full of stories about bushrangers, cricket, family and friendships with, and injustices suffered by, the local Aborigines. Now, not one single thing in this book can be proven scientifically. But it is still completely reasonable for me to say that I know my family history, and that the only way I can know it is through this sort of eyewitness testimony.

In arguing for the sole reliability of scientific knowledge, Boghossian is wrongly arguing for a position that he holds in common with most of the so-called New Atheists. Philosophers call this “scientism” and almost to a person they recognise that it is a silly position to hold. Atheist philosopher Massimo Pigliucci says that “what really characterises the New Atheism, as distinct from previous versions of atheism, is its marked turn toward scientism … I maintain – as a scientist and philosopher – that such a move has been a bad one for public atheism, [because] scientism is philosophically unsound.” Indeed it is really only the militant New Atheists who like to argue for it. It is easy to see why they try though. Since the existence of God or the supernatural can’t be conclusively proven by the scientific method, people who follow “scientism” can then argue that belief in such things is baseless and probably delusional.

But here there’s a great irony. Scientism is revealed to be an extraordinary and unsustainable way of thinking about knowledge, whereas Christian belief is based on all the ordinary ways of knowing. Christians sensibly ground so many of their ethical and existential beliefs in intuition. Christians put their faith in Jesus in large part based on the eyewitness testimony to the historical events of his life, death and resurrection. Christians know God personally through the presence of the Holy Spirit and they experience his power through miracles like healing and visions.

Of course, Christian belief in these things is extraordinary. But it is extraordinary because God is extraordinary. The way we come to these beliefs is remarkably ordinary, and it’s on account of that “ordinariness” that it is reliable.

Richard is a part-time Research Fellow at the Centre for Public Christianity. He is also Director of the Centre for the Study of Islam and Other Faiths at Melbourne School of Theology, and part of the Understanding and Answering Islam team for Ravi Zacharias International Ministries.