This presentation was made by Hélène Mottier, PhD student in Cognitive Psychology, on the occasion of Young Researchers Meetings of the Laboratory of Psychology and NeuroCognition, 2019 edition. It took place at the bar Dr D. (Grenoble) 11 July 2019. >> Re-editing for Echosciences Grenoble <<
Explaining science is not easy. There is the difficulty of making accessible knowledge built through a process that is not used on a daily basis. There are also language barriers: the various scientific fields use a very specific vocabulary, often long to explain. Add to this individual beliefs that can go against scientific knowledge, information -and misinformation- give us briefly without knowing their source, speeches that use the sciences for ideological purposes, and you have there a very toxic mixture to unravel the scientist of the non-scientist.
Faced with this flow of information, understanding how scientific knowledge is different from other forms of knowledge is essential to forging critical thinking. And so that we can understand, we need to be explained in a way that does not deform them. In this presentation, I will start from the title that I will develop in three points:
Part 1. Expliquer Sciences : What differentiates a scientific knowledge from an unscientific knowledge? What is the scientific approach?
part 2. Disfigure the sciences I will give three examples of "disfigurement" of scientific knowledge that can also be heard by scientists.
part 3. Challenge of popular science I will explain here why I believe that spreading science is a challenge, not a skill.
The sciences have achieved their nobility in the arguments because they are valid knowledge that describes the real faithfully and neutrally, compared to other forms of subjective or ideological knowledge. But this validity and neutrality of scientific knowledge are not self-evident.
An element that seems fundamental to me to explain the sciences is precisely to recall the fundamentals: why am I told that such scientific knowledge is more valuable than my subjective knowledge of the world?
In other words, it is appropriate in his speech to recall how the scientific knowledge that I present is different from another form of knowledge on the same subject. To do this, it is important to speak about what constitutes the pillars of the construction of scientific knowledge: the scientific approach and the criteria of demarcation between science and non-science (2 slide).
1.1. Scientific knowledge
Scientific knowledge is a valid description of the real. Valid in the sense: valid for all. For knowledge to be valid for all, we need objective measurement tools.
For example, if I want to measure this great road in Grenoble (3 slide), I can count the number of steps I take from one end of this road to the other. But this measure is subjective: it depends on the size of my legs, and my stride will never be quite the same. Another person who has legs bigger than mine will not fall on the same number of steps. In science, my point of view and that of the other person should not be taken into account in the measure of reality, at the risk of an interminable discussion that will not teach us much about the size of the road ... make a description that will be valid for this person and me, so it will be essential that one is provided with a meter, a measure certainly arbitrary but with which one will fall on the same results (and if it is not the case it will be easier to discuss what creates measurement differences with exactly the same tool).
Another important element to remember is the fact thata scientific knowledge can not, by definition, to be apprehended spontaneously. Even if some scientific knowledge may seem "intuitive", they only have the status of scientific knowledge if they have gone through an objective measurement process (see 1.2, the scientific approach).
Also, you can not study everything in science.
The 4 slide represents what is in the realm of knowledge and what is outside. Scientific knowledge is part of the domain of knowledge (orange zone): it can be tested and observed. Some scientific knowledge attains the status of "scientific knowledge" or "scientific consensus": these are the best valid descriptions of reality that we currently possess (black zone). Scientific research is located around this scientific knowledge, we seek to gain ground in the field of knowledge (red zone). On the graph, however, we see that a very large part of the field of knowledge is still part of what we do not know. However, these are knowledge that can one day be described and explained scientifically.
All around this area of knowledge lies what one will never know and which one can not study in science (white zone). This white area is not uniform, but to avoid dwelling on this question which is not the substance of this presentation, we include in this area everything related to beliefs, whether ideological, spiritual, morals etc. These are elements that are the business of opinion as logical reasoning but to which we can not apply a scientific approach. In fact, some conversations go around in circles because we are talking about the same thing but not referring to the same "zone".
One can thus find oneself in a conversation with as central subject "the thought. But, while a person will talk about the scientific underpinnings of thought (thought as behavior and / or associated cerebral areas), the other person will instead talk about thought by referring to metaphysical foundations (the soul). If you do not want to go around in circles or fight, then it's important to know what area you're referring to. The two foundations (scientific and metaphysical) are interesting but they are two areas of reference that are difficult to compare. This brings us to what distinguishes scientific knowledge from other forms of knowledge: the construction process and the demarcation criteria.
1.2. The scientific approach
The scientific method aims to describe and explain the facts (the real) in a neutral way. Conversely, the ideological method will try to match the facts, the real, with the conclusions (slide 5). This method is therefore not neutral and two competing ideologies will thus present the facts from different angles. Similarly, the same facts presented with a scientific or ideological method may be in competition, and in this case, it is important to know how knowledge was built in the scientific process to form a critical opinion.
All scientific knowledge is built through a process. I will first state a hypothesis, that is, an affirmation, related to current scientific knowledge (the black box on slide 4). I will then plan a way to test, to objectively measure my statement: I put my assertion to the test. I will then observe and obtain results that must be quantifiable. From these results, I will conclude on my assertion: do my results on the facts go in the direction of my affirmation? Or is my statement rejected? If the results do not go in the direction of my affirmation, then my assertion was not a good description of reality. If my statement is not rejected, the facts are in line with my hypothesis, so my statement seems to be a good description of the real. Thus, unlike the ideological method, the conclusions do not always go in the direction of my affirmation: I seek to describe the real as it is, rather than to describe the real as I would like it to be.
If I insist so much on the fact that my hypothesis is an affirmation, it is because it is a criterion of demarcation between science and non-science: my hypothesis, to be scientific, must be refutable.
1.3. Criterion of demarcation
La falsifiabilityis the ability of a hypothesis to be clear, precise, and to give direction: This clear-precise trick causes this thing-clear-precise. By following this line test, so I can test my proposition and if my results are in line with this statement, or if it rejects: I see that this thing clear, precise because this thing clear, precise. Or not. This is one of the most difficult exercises of scientific research. Anyway, if you are presented with an assumption that is not refutable: this not-clear-all thing has a positive influence but not always depending on the circumstances on this-what-do-not-do-not-define thingThis means that it is difficult to advance scientific knowledge (the black zone).
The other criterion is principle of parsimony or Ockham's razor (slide 7): for our hypothesis, we start from knowledge that we already know, that we can already explain, rather than knowledge that asks even more questions. If my door slams and there is no one else than me in my apartment while I am comfortably settled on my couch writing this presentation for some time, it will be more parsimonious than I emit l hypothesis that it is the wind (a known, observable phenomenon that I could test) that caused the door slam, rather than a ghost (even though I screamed in fear). The principle of parsimony supposes to state hypotheses which remain in the domain of knowledge (orange zone of the slide 4). Yet I could never observe with my eyes neither the wind nor a ghost slamming the door. But I can know the properties of the wind (and of my door) and I can measure objectively the effect of the wind on my door, which is not the case of the concept of ghost. This is why we often say that something is undemonstrable. I do not have the skills to test the wind hypothesis on my door, but it would be quite demonstrable since these are concepts that are part of the domain of knowledge.
The refutability of hypotheses and the principle of parsimony are the criteria for the demarcation of scientific and non-scientific knowledge. If these criteria are not respected, the scientific community does not consider knowledge as scientific, even if the scientific approach has been respected. So beware of "scientifically proven" claims, let us first ask if the hypothesis is parsimonious and if it is refutable.
Finally, in a study that tests a parsimonious and refutable hypothesis is not enough to form a scientific knowledge, this study must be replicated, identically, with different measures and that one consistently falls on the results that go in the direction of this hypothesis. We say that the replications have a very strong level of evidence.
1.4. Levels of proof
Scientific replications do not carry the same weight as personal opinion when it comes to meaningfully describing the real. This is not to say that a person's opinion is good or bad, simply, if the discussion is about whether or not something better describes the real, then we can not give the same level of evidence to replications and opinions. I can have my opinion about the door slamming and be convinced that it is a ghost. But if another person replies a multitude of times his study and proves that the wind describes very well the phenomenon observed (my door slams), this person has better evidence to describe the real.
Similarly, if a person makes a scientific study respecting the criteria of demarcation and the scientific approach, and that this study contradicts a scientific consensus (replicas of study which all go in the same direction), the study isolated is a lower level of evidence than the scientific consensus. It may turn out that this study is a premise of a new scientific knowledge that will be consensus and that it will prove better to describe the real, but as it stands, it is not enough.
It is important in the speech that these levels of evidence are clear. We often see media debates where two or three speakers do not agree on a fact, but it is rare that these people have the same level of evidence. Personally, I give more credit to the evidence of the person who has a scientific consensus, because his level of evidence is better at describing the real. On the other hand, I tend to open my antennas as skeptics when they talk to me about science but they are disfigured ... to follow here.
Part 1 References:
Chalmers, A. (1990). What is science? recent developments in philosophy of science: Popper, Kuhn, Lakatos, Feyerabend. Paris: The paperback (no 4126).
Popper, KR (1980). Objective knowledge
Popper, KR, of Launay, MI, & Launay, MI (1998). Sources of knowledge and ignorance. Payot & Rivages.
Site of the Cortecs: https://cortecs.org
Several images and remarks are taken from the work of the chain Mental Hygiene that I strongly recommend you to watch: https://www.youtube.com/user/fauxsceptique
Thanks to J. Bena for reviews and comments.
For the sake of readability, the 2 & 3 parts of this presentation are grouped in a second article: to follow by clicking here.