Abandoned church in Italy. Photography by Roman Robroek from a series on abandoned houses of worship in Europe. Used with permission.

It’s now more than twenty years since I left Christianity and became an atheist. There was no Damascene conversion; like many people I drifted away rather than having a sudden insight. A series of events and discoveries led me to finally break from the church, although it took moving country to finally sever the social bonds and expectations that had kept me involved long after I would otherwise have left.

It’s been a long psychological journey from growing up as a creationist in a church of Biblical literalists (not the extreme Young Earth kind, but close enough) to becoming a professional academic biologist who teaches evolution. In that time I’ve established a career, worked all over the world, started a family, lost some friends and gained many more. All the turbulence that makes up a fairly normal life. Neither the good times nor the bad have led me to reconsider my position on religion.

The last two decades were also a period during which the tension between science and religion broke into mainstream discourse. A number of prominent atheists derided what they saw as unreason; none of the arguments were new but their vehemence and prominence were unusual. Of the main figures, the most persuasive was Christopher Hitchens, a man by all accounts possessed of magnetic charisma, compelling in debate and uncompromising in his writings. Other notable contributions were Dawkins’ The God Delusion and PZ Myers’ Pharyngula, for a while the most-read science blog on the internet. None of them influenced my decision because I had already become a convinced atheist before I encountered any of them.

Times have changed as the main protagonists have died, become caricatures of themselves, or merely declined in profile. It would be nice to think that people grew tired of hearing angry old white men argue with each other. They certainly didn’t succeed in making religion disappear and were likely a symptom of declining religious belief rather than its cause. While tempers on the subject have cooled, at the same time I have matured and become more reflective, and it’s now possible to look back on this period with a degree of detachment.

One of the ways in which leaving religion is described is as ‘losing your faith’. This is worth interrogating a little further. The Apostle Paul gives the following definition of faith, the only explicit one to be found in the Christian Bible:

Now faith is confidence in what we hope for and assurance about what we do not see.*

The basic point is that faith means believing in something despite not having complete or direct evidence for doing so. This seems as good a definition as any to me; I don’t know whether other religions have similar ones in their sacred texts. Put simply, you don’t need faith if you have incontrovertible evidence.

Much of the modern rationalist case against faith in general, and the Christian religion in particular, can be traced back to this verse. It is a prima facie example of how religious belief requires the absence of evidence, in contrast to scientific rationalism, which only allows for belief in things which can be directly proven. Religious truths are obtained through divine revelation, and are hence diverse, whereas scientific truths are produced via rigorous enquiry, which means that eventually they should hone in on a single answer.

The strongest proponents of scientific rationalism declare it to be impossible to be a true scientist whilst also holding a spiritual belief. This is clearly not the case; many scientists worldwide are religious. I know a good number and think no less of them. Whether the two positions are intellectually incompatible is not something I want to get into here, although I will note that we all manage to sustain contradictory viewpoints on many things. It has been claimed that biologists are less religious than other branches of science, but the evidence for this is inconsistent, and may to some extent reveal social norms within fields rather than any link with the subject material or mode of enquiry.

Regardless of whether I might describe myself as not having a faith, I expend a lot of my time believing fervently in things for which I have no direct evidence, at least not yet. What is ‘confidence in what we hope for‘ if not the anticipated outputs section of a grant proposal? Past evidence of over-ambition has not changed my approach to these.

As for ‘assurance about what we do not see‘, there’s more to this than believing the results of papers which we can neither replicate nor access the underlying data or code. Even were we are able to do so, we usually lack time and resources to check. Instead we invest our trust in institutions (journals) or authority figures (other researchers) whose work we often accept without direct scrutiny. Given that we can’t check everything, we place confidence in the peer review system to rigorously inspect claims, despite personal experience of its occasional flaws. The difference between something I could check, at least in principle, and something I will accept without further question, is semantic insofar as how I respond is unchanged in practice. Such intellectual shortcuts are standard for everyone.

Moreover, our field (like most in science) is littered with fundamental theorems which work in closed or simplified systems but come unstuck when faced with the complexities of the real world. This doesn’t mean that they’re incorrect, but rather that uncovering the evidence for them is harder than we assume. If you’re an ecologist then perhaps ask yourself how often you’ve thought to directly test the logistic model of population growth, equilibrium model of island biogeography, Tilman’s R* or any number of theories which for many of us form the cornerstones of our understanding. If you have then my guess is that it didn’t go as smoothly as you hoped.** For the most part our evidence base derives from a surprisingly small set of case studies. Other theories for which the jury remains out (e.g. Metabolic Theory of Ecology) have advocates who by very definition are basing their belief on incomplete evidence given that other critical observers remain unconvinced.*** Is believing something because logically you feel it must be true that much better than accepting something without direct evidence?

A few weeks ago I stood on a seashore and stared at a rock covered in barnacles. The patterning was inconsistent with a model of their organisation which I’d published a few years ago. What went on in my mind was not a collapse in confidence but rather a reconsideration of what other processes or factors I might have been missing. I looked at that rock still believing in some version of the model even while the evidence in front of me so obviously disagreed. If I continue to work on this system then I remain certain that the model can be recovered, and have a few ideas of how to go about it. What is this if not a form of faith?

All this comes round to a recognition that perhaps I didn’t lose my faith; I simply realigned it by investing in a different set of principles and authorities. God disappeared from my worldview but maths and the scientific method took over. I may believe that my work is in pursuit of truth and serving a higher purpose****, but this this any different to those who follow a spiritual calling? In the last twenty years I have certainly changed but perhaps not as much as I thought.

* Hebrews 11:1 in the New International Version. The remainder of the chapter goes on to give historical examples of faith in practice.

** In writing this I am in no way questioning whether any of these fundamental theories is correct. Well, maybe the equilibrium model.

*** For the record, my take on metabolic theory is that it must be correct on some level but perhaps we haven’t been able to characterise natural systems in the appropriate way. I’m planning to have a chapter on this in the next edition of my textbook (don’t start getting excited just yet).

**** If you agree with me that understanding trees and barnacles represents a higher purpose then we really should be friends.

CODA: having swum in these waters before I know that taking a conciliatory line on religion and science is likely to see me being savaged by both sides. So let me be absolutely clear about my own position before anyone assails their favourite straw man. I am a scientist, humanist and atheist. I am convinced that the scientific process, whilst sometimes flawed and inefficient, remains the best means of deriving facts about the world. I hold no spiritual beliefs of my own but respect those who choose to and do not question their personal reasons. In response to this post I welcome constructive discussion that aims to increase mutual understanding but will not allow any comments which do not meet this standard, regardless of the viewpoint they seek to advance.