By John Atkinson 

The idea is increasingly being propagated that we live in a 'post truth' world. In this world, 'fake news' has supplanted genuine news and we can no longer believe the words of our rulers or the media that we see, hear or read. Implicit in the idea of a 'post truth' era is that this follows a 'truth' era. This would have been a mythical time when our leaders spread news to us that was the truth, the whole truth and nothing but the truth. That mythical time appears to have passed me by. Perhaps others remember it with some clarity.

In truth (ha!) the stories we receive have always been partial. Partial in the sense that they were incomplete and partial in the sense that this may not have been by chance. They favour some part of the landscape. Always the story teller has not seen the whole picture and always that story teller has had to make choices as to how much of their story they are able or it is helpful to share.

Sometimes this is a measure of their skill as a story teller. Even ascribing the noblest of intent, the art of building a compelling tale, weaving together the plots and sub-plots, heroines and supporting characters has proved a challenge for history's finest exponents of this art. Even the finest artisan will never hold all the pieces. Others bring a fresh take to events we thought we understood. Our own recollection fades or is coloured by others' perception.

The nature of complex systems is that there can be multiple and competing truths that are all valid. This is not a surprise to the physicists who tell us that matter may be particle or wave depending on what you look for. It is not a surprise to the accident investigator who finds people have differing recollections of what actually happened and that over time these begin to conflict with even their own contemporaneous accounts. It fits with Thomas Kuhn's sense of prevailing scientific paradigms that bound our thought until the anomalies become too much to bear.

And sometimes our story telling is deliberately disingenuous. We hold values that have been hard earned that matter to us. We tell stories that demonise and undermine those that oppose us. We leave out information that we find hard to believe or objectionable. We bend our version of events so it better fits the telling.

Human cognition is constantly framed by our perception, by our feeling and our values. The more we learn about how we perceive things, the more we discover that our rational process is post-hoc. We are decided on 'what is' long before the evidence is processed and our story emerges. We see what we already know and find it hard to see what is previously unknown. The brain matches new phenomena against existing patterns as a way of determining what is really going on.

There was no mystical era of truth and our news has always been as fake as it is true. Pontius Pilate asked 'what is truth?' at the trial of Christ. He was no nearer getting an answer then than we are today. Or was the Gospel of John fake news?