Fact, Truth, and the Scientific Method

Is there such a thing as a geological “fact map”? Can we justify the widely used term “ground truth” to describe such a map, or indeed any direct geological field observation? This is not just a question of semantics. Surface indications of ore are usually subtle, and your predecessor’s claim that their observations represent “fact”, let alone the “truth”, should never be taken at face value. Yet these descriptors are very commonly used by economic geologists. The purpose of this essay is to persuade you that we should abandon these terms.

A map is a two-dimensional virtual reality representation of a portion of the earth’s surface. A geological map is an artifact constructed according to the theories of geology and the purpose of its maker in putting it together (i.e. his or her biases). It presents a selection of field observations and is useful to the extent that it is a graphic which aids the prediction of things which cannot be observed. There are different kinds of geological map. With large‑scale maps (i.e. detailed maps of small areas, generally 1:500 to 1:2500 scale), the geologist  aims to visit and outline every significant rock outcrop in the area of the map. These are often called “fact” maps or even “ground truth” maps acquired through a process of (ouch) “ground truthing”.   But geologists, indeed all scientists, should scrupulously avoid the words “fact” and “truth”.  A much better descriptor for such maps is “observational” or simply “outcrop”. In a small‑scale map (which covers a larger area: but the terms small-scale and large-scale are relative), visiting every outcrop would be impossible. Generally, only a selection of available outcrop is examined in the field and interpolations made between the observation points. Such interpolations may be by simple projection of data or by making use of features seen in remote sensed images of the area, such as satellite imagery, air photographs, aeromagnetic maps and so on. Small‑scale maps thus generally have a much larger interpretation element than large‑scale maps, but no geological map, at whatever scale, is ever free from interpretation, or from the biases of the observer.

Outcrop geology map

A portion of a large scale (the survey pegs are 40 m apart) outcrop geology map, called by some a “fact” map. The author was an economic geologist: his biases and purpose in making the map are obvious. Another geologist, with different biases, would have made a very different map. Click for larger, sharper image.

“Fact”, and the related but more portentous idea of “truth”, are abstract ideal concepts. They are loaded words that are too often used as a means of asserting authority and preempting debate. When you say, “this is a fact” you are saying, in effect, “you may not dispute this”. When you say, “this is the truth”, the unstated implication is that those who disagree with you are deniers, heretics or contrarians. Recall, from your own experience, how often in debate these phrases are used to introduce a controversial statement that the speaker knows you might well not accept and wants to ring-fence in advance against your anticipated skepticism. Phrases such as “in fact…” or “the truth is..” are standard figures of speech that we all use in conversation as a means of emphasizing the strength of our belief. You are entitled to respond: “that’s not a fact, it’s just your opinion” – or – “where’s your evidence?”  But quoting “fact” and “truth” are always to weaponize these words in pursuit of an agenda (i.e. to win the argument or convince a doubter). Evidence for this abounds from all fields of communication: the words “fact” and “truth” are stock phrases used in advertisements to convince you to buy a product; they populate the language of journalists and of politicians[1] trying to convince their readers or influence their electorate.

The current proliferation of “fact” checkers on Social Media platforms, web sites such as politifact.com, factcheck.org or cfact.org, or on “our” ABC, assume a god-like knowledge and ex-cathedra authority that never acknowledges, or is apparently even aware of, their own potential biases. The Royal Melbourne Institute of Technology (Australia’s second largest university, RMIT) even offers its undergraduates a course on fact checking.  Google, Facebook, the ABC and RMIT, along with many other media organisations worldwide, are members of the International Fact Checking Network. IFCN is a division of a small South Florida Journalism school called the Poynter Institute. As well as the IFCN, the Poynton Institute also operates the politifact.com and mediawise.com web sites.

truth o meter

The Truth-O-Meter: a graphic used by the Poynter Institute to illustrate their opinion.

Who are these self appointed Custodians of Truth?  Perhaps a panel of retired Judges experienced in impartial judgement and the sifting of conflicting evidence? Perhaps a range of scientists with appropriate knowledge of a subject and a lifetime of applying the Scientific Method? Perhaps a broad spectrum of randomly-selected citizens impaneled to select between competing claims on the basis of life experience and common sense?  Perhaps a military style blue team red team approach? No, none of the above, but “journalists and media experts”. And not just any journalists out there in the real world filing copy for a living, but salaried academic journalists in media schools, operating within the green-left alternative universe that seems to be the environment of most of today’s Western Universities. That last sentence, of course, is an opinion.

Guardians of Truth (cropped)




Custodians of Truth: participants at the International Fact Checking Network Summit, Cape Town 2019

My objections the groups operating under the umbrella of the IFCN is not with their stated aims (which are noble) or their conclusions (which I might well agree with) but in their use  of the words “fact” and “truth” in order to award themselves the mantle of authority and infallibility.  If they were called, and operated, as “evidence checkers” they arguably would have a useful role to play, provided they presented all the evidence, in a fair and balanced manner.

Quis custodiet ipsos custodes? 

A good example of the distinction between evidence and fact comes from the field of criminal prosecution. Lawyers prosecuting or defending a person accused of crime present evidence – often conflicting – to an experienced judge or a randomly-selected, 12-person Jury. It is the job of the Jury to determine “fact” by giving a guilty-not guilty verdict. But the legal definition of fact to which they must adhere is limited and qualified. It is an opinion to which all 12 Jurors must agree and which they consider to be “beyond all reasonable doubt”. And in spite of this laborious and time-consuming process, fine-tuned over centuries of jurisprudence, they often get it wrong.

At the most fundamental level, the ideas of objective fact and truth are ideal philosophical concepts that we can only seek to achieve. Claims of absolute fact and enduring truth belong to the realms of faith and belief[2]. The Scientific Method is not based on faith or belief but on evidence. Evidence (and its digital version, data) is not the same as fact, though the two ideas are often conflated. “Alternative evidence” is the proper subject of much scientific discourse: “alternative fact” is an oxymoron[3].

This is not to dispute that an observation (evidence) can be so well established by universal experience that for all practical or everyday purposes can be called a ‘fact” that few rational people would dispute without being dismissed as a boring pedant or a nut case (maybe you already fit me with one of these hats?). That the sun rises in the east or that the earth is round are all, by this definition, statements of fact[4]. But, to return to the main subject of this essay, when a geologist produces a large-scale outcrop map and calls it “fact” or “ground truth” I do not think we have to accept that his or her lines on a piece of paper can be described with the same level of certainty.

Sun rises in the east

The sun rises in the east. Fact…or an optical illusion?

On reading the above paragraphs I realise that I run the danger of straying into the area of post-modern philosophy called Relativism. Relativism denies that there is any objective truth out there: all systems of knowledge and ideas are social constructs and all such constructs, from Dark Matter to the Dreamtime, have equal validity. That is neither my opinion nor the point I wish to make. My point is this: in their professional writings Scientists should avoid using the words “fact” and “truth” and accept that all their observations and theories are subject to scrutiny, qualification, and skepticism.

In the real as opposed to the theoretical world, truth, like beauty, is in the eye of the beholder. One observer’s “ground truth” could be another’s irrelevant noise.

(This post is a greatly expanded and rewritten update of a previous post first published in 2015, entitled: “Is there such a thing as a geological fact map?)


[1] For maximum impact, Al Gore’s 2006 disaster movie was titled “An Inconvenient Truth”. As an ex-politician he knew the technique. A technique good enough to win him a joint share of the 2007 Nobel Peace Prize.

[2] The legendary editor of the Manchester Guardian, C P Scott, acknowledged this in 1921 with his famous quote: “comment is free, but facts are sacred”. A noble sentiment, but how could he, or the generations of journalists who followed,  be sure they always know the difference?

 [3] When Donald Trump’s campaign manager Kellyann Conway used the phrase “alternative fact” in a 2017 interview she was widely ridiculed. “Alternative facts are not facts” spluttered her interviewer “They’re falsehoods”. And he was right.

 [4] The sun does not “rise” – this is an optical illusion, but an illusion good enough to fool the best brains of humankind for millennia. And the earth is not round – not even spherical:- this is a convenient simplification, but a simplification good enough for everyday discourse. The earth is, of course, a slightly lumpen oblate spheroid. 

Comments are closed.