Would you rather be the rat or the flea?

We must have debated this roughly once a month. It would be during those drawn-out hours between afternoon and evening when the rusty light puddled through the low windows of the Talbot Arms and turned everything sepia. It was a small pub, the walls covered with hunting paraphernalia and pictures of gun dogs, but it was conveniently located on the outskirts of the city, only a short walk from the campus. It was usually on Tuesdays or Wednesdays – those marooned days where the comfort of the weekend still seems far off – that we would find an excuse not to go home after we finished teaching our classes and instead gathered at a table in the furthest corner of the pub. At that time I was still reeling from the end of a long relationship, while Tim was divorced and Josie had the air of one of those permanently-distracted women who go out of their way to avoid anything so messy and hazardous as romance. In short, one of the reasons we hid away there after work was because none of us were in any hurry to head back to our empty homes.

There were other things that bound us together, of course. We were all loners, through choice or necessity, and all of us were dealing with the receding horizons of our ambitions, stuck as we were in a small parochial town at a second-rate university. We were also all drifting towards the outer fringes of our respective fields (Tim in physics, Josie in biology, and myself in the lumpen pages of ancient history), with little to encourage us to return towards the respectable middle ground. Yet I cannot help but think that it was the sense of remoteness that most marked our meetings, and in retrospect I believe it was also this that most clearly informed our ideas.

If there is one thing lonely people hate, it is having to talk about themselves. And so our conversations avoided daily life (the petty bureaucracy of research grants and undersubscribed courses; the mundane trials of living alone) in favour of the abstract. At heart, I believe it was a question of size. Perhaps I am being reductive – I am no scientist, and I cannot claim to have always understood the nuances of their respective arguments, yet nonetheless since I was usually sat in the middle I somehow found myself in the awkward position of a judge trying to arbitrate between them.

Tim would be on his fourth or fifth half of bitter (a whole pint never tastes quite as good, he explained) when he would start on that familiar tack. A common bugbear was over-eager undergraduates asking him about the implications of the experiments then being carried out in the Large Hadron Collider at the Cern Laboratory.

‘It’s not that I begrudge them their enthusiasm,’ he would explain. ‘God knows, I was like that once too. The Higgs Boson is by far the most important discovery in our lifetimes, but it would be wrong to think it answers every question we have about the universe. Such giddy excitement is misplaced. Even if one day we can define dark matter or gravitational waves, or even if someone comes up with a unified theory of everything, there’s still never going to be a single key that unlocks all the secrets we’re looking for, not least because even if there were it would be outside our understanding.’

‘You’re saying that there’s a limit on scientific understanding?’ I replied.

‘Of course. I’m not alone in thinking that, but it’s something many scientists like to keep quiet. Didn’t you ever wonder why you find so many more religious people – Jews, Christians, Muslims – in the Sciences than in the Humanities? I think its because we better understand the limits of our field.’

‘What do you mean?’

‘Think about it. It’s commonly agreed that the meaning of a system can only be imposed from the outside – it cannot be recognised from within. A single computer chip cannot guess at the working of the whole computer, nor the images rushing by on the screen. It is, therefore, a logical fallacy to assume we can deduce meaning from within the very system we are contemplating – we are small parts of it, tiny cogs, and there is no more chance of us understanding the secrets of human life, or the intimate workings of the universe, than of a single grain of sand understanding the Sahara.’

For Tim, meaning lay beyond our reach. We were a part of an intangible code and thus far too small to view the puzzle from without. Looking back I am not sure whether we turned to grand and recondite ideas, to the hypothetical and theoretical, because we were fed up with thinking about the minutiae of our own lives, or simply because we could not bear to. Regardless of which was closer to the truth, we were in a rut. Nothing repels potential friends and partners more than the reek of loneliness and desperation, and so until we managed to cast it off we were stuck.

Josie, meanwhile, seemed to argue a similar point from the opposite perspective. She would be fussing her great mane of grey curls distractedly as she spoke, her voice slow and halting, as though it was something of a struggle to translate her ideas into speech.

‘I’m not sure I can agree. You’re thinking too big. If meaning exists, then it is not outside us but within.’

‘Sorry, but that sounds like a load of mystical mumbo-jumbo.’

‘Then you’ve misunderstood. I mean literally, at a microscopic level. I don’t think we are within a system trying to figure it out. I think we are the system itself. I spend my days researching pathogens and let me tell you, there’s nothing more fascinating. There’s a stark beauty in their genetic evolution, if beauty is the right word. Take gonorrhoea, for instance.’

‘I’d rather not!’

‘No, but really it’s a wonderful example. First of all, the bacterium has adapted so as to be able to resist antibiotics. Now that’s relatively common in advanced pathogens – it’s something we see all the time, and it makes treatment more difficult than ever. It’s a basic survival mechanism: adjust, adapt, evolve. But while it takes your typical species hundreds of thousands of years to make even the most basic of biological changes, a pathogen can do it in months. They have the advantage against us. In comparison we are slow, basic, outdated primates. But more importantly, gonorrhoea has not just adapted to our medicines, they have also adapted to us. In the past, soldiers would complain that they knew they had picked up the infection because when they visited the bathroom it felt, if you will excuse my French, like pissing shards of broken glass. Modern sufferers, however, will often not feel anything at all when passing urine.’

‘It’s become painless?’

‘That’s a crude way of putting it, but essentially, yes. In that way the bacterium can avoid detection, and so survive longer. By minimizing the manifestation of outward symptoms, it protects itself against discovery and the possibility of treatment. It’s a perfect strategy of almost military precision, and its all achieved by the most basic of pathogens with just a few adjustments, with no working brain or consciousness necessary.’

‘Are you saying that they are more advanced than humans?’

‘Not at all. I’m saying they don’t need to be. We’re simply hosts. I’m beginning to think that there is no better meaning than that. We exist because we are the perfect hosts for harbouring pathogens. We cannot evolve fast enough to escape them. We’re houses, if you like, and like houses our meaning is ultimately derived from our practicality. Do we fulfil our function? The answer is clearly yes, as far as viruses, bacteria, prions, fungi or other pathogenic micro-organisms are concerned.’

‘So you’re saying our purpose is simply to be carriers? That’s the meaning of existence? That we’re rats, our purpose simply to support fleas?’

‘Exactly.’

It was around this point that they began to argue in earnest, but I am afraid after all this time the intricacies of their finer arguments escape me. Suffice it to say that I was never sure which was the more hopeless prognosis: that meaning would lie forever beyond us, or that our meaning existed only at the genetic level. Either we are the flea – unnoticeable, tiny, irrelevant to the grand scheme of the universe – or the rat – at the mercy of the smallest creatures living upon it.

We turned to these ideas, I believe, because there is a peculiar comfort in recognising your ultimate irrelevance. It makes the small problems of daily life so much more bearable. We fought loneliness with ideas that made human life something faintly ridiculous. It did not matter who was right. Either way, life was beyond our control. Either we are too small to unpick the intricacies of the giant system we are part of, or else we are the outsized feeding grounds for millions of microscopic organisms that allow us to evolve only so we can incubate them and provide them with homes.

The three of us continued to meet and debate this question for the best part of a year. Then, all of a sudden, things began to change. Tim started dating a woman who worked in HR, Josie was awarded a research grant that allowed her to travel with an elite team to South East Asia for a special research project on the resurrection of a number of extinct diseases, and I decided to take up a job abroad. In short, the story had something of a happy ending. Like Josie’s pathogens we adjusted and adapted in order to carry on. In the end, it seemed it really was a question of size, since it was only once we cast off the big, abstract ideas that we were able to fall back into the smallness of our own lives.