An episode in the latest series of Dave Gorman’s Life is Goodish caused me to wake my snoozing sofa companion with mild alarm when I exclaimed, “And that’s why you don’t fact check with Wikipedia!”  The reason for my outburst goes something like this: Dave Gorman discovered that someone had added a statement on his Wikipedia page that was untrue. This statement was then reported as fact by a local newspaper. Several other local newspapers did the same, giving the story widespread credence. When Dave Gorman pointed out the false statement on Wikipedia was, in fact, false, it was promptly removed, only to reappear sometime later, this time with a footnote to the first newspaper article that had reported the incorrect statement from Wikipedia in the first place.

The circularity of this set of circumstances, which resulted in a lie being given the veneer of truth, thanks to the inclusion of a superscript number in a pair of square brackets, neatly sums up the political landscape in which we appear to find ourselves. We now inhabit a Wikipedia world; a world in which everyone gets the opportunity to editorialise according to their own inclination and/or impishness. Not only do we inhabit this post-truth world, in which facts (as slippery as they can be) are only facts if people chose to believe them, and if not can be discarded as swiftly as an ex-X-Factor finalist, but we seem also to live in a fantasy footnote world, where sources can be made up and scattered throughout the internet like gold-plated confetti at any one of Trump’s three weddings.

I’m a fan of the footnote. Footnotes support analysis and interpretation, they can provide proof of objective facts, offer evidence for supposition and conclusion and they signal the research structure around which good historical writing is built. But the mere existence of footnotes does not make something factually accurate. They offer a breadcrumb trail that can be followed, to find that bedrock of both historical research and contemporary reportage: the source.

History is all about sources and they come in all shapes and formats: written, visual, oral, quantitative, qualitative, political, economic, social, formal, informal. From amongst the jumble of sources available to us (including those that are absent: the sources that have been silenced, lost, ignored or destroyed) the past can be jigsawed together. But those sources should never be taken at face value; they should always be read critically and approached with respectful caution, because no source is unproblematic. We teach students of history to ask searching questions of historical sources: how reliable is it? who wrote it? why did they write it? can it be verified? what evidence is there to support it? The study of history demands that we consider concepts such as bias, subjectivity, objectivity, provenance, motive and audience, in order to think critically and analyse intelligently. And the present demands no less of us than the past. This is why history is so important, for when we learn how to question the past, we learn how to question the present.

At a time when we have never had so many facts, when social media has broken down the old ways of creating, transmitting and consuming information, we have never needed the skills of the historian more. Fake news items have not only permeated our culture, but also our political discourse and have the potential to threaten our future safety. Facing a post-truth future, we need history to remind us that the mere existence of footnotes verifies nothing. It’s where the footnote might lead us that matters. We need to follow the breadcrumbs, and then to analyse and assess in order to make informed judgements as to whether the sources we find are objectively accurate, rooted in reality and verifiably true, rather than merely leading back to themselves and verified only by their existence on a Wikipedia page.