PROOF BY FACT
PERSUASION AGAINST FACT

A statement about a concrete fact is refuted by the observation that it is contradicted by reality: “Pierre (is French, so he) has red hair ” is refuted as soon as you observe that Pierre has brown hair. The affirmation of a general fact “all Syldavians have red hair” is falsified by a simple counterexample, “this Syldavian is brown-haired”.
But the effect of facts on beliefs is much less clear than these examples suggest. The “web of beliefs » and the “web of facts » function as parallel networks. An embarrassing fact can be dealt with by declaring the fact to be marginal or misobserved. It can also be admitted as an imperfection in the web’s meshes.

1. Falsifying a statement of an empirical fact by showing that its opposite is true

A statement of fact can be made as a report of directly observable evidence or as the conclusion of an argument: « You are very flushed, you feel tired, you probably have a fever. » Every argument contains such statements all of which can be contradicted and refuted.
In philosophy, « an atomic fact is the simplest kind of fact, and consists in the possession of a quality by some specific, individual thing » (SEP, Logical Atomism). An elementary proposition reports such an elementary fact.
In natural language we can assume that the elementary proposition ascribes to a being a property that is empirically evident and therefore empirically refutable.

The assertion of a concrete fact is refuted by the observation that it is contradicted by reality: “You say this, but I observe that”. This is an application of the principle of non-contradiction; the rule of opposites states that two terms that are opposites cannot both be true of the same subject.

Statement: Pierre has brown hair
Observation: Pierre has red hair
Application of the Rule of Opposites: “black” and “red” are opposites; they can be simultaneously false, but they cannot be simultaneously true. The statement Pierre has black hair is disproved

The alleged fact and the established fact must belong to the same class of opposites: one does not refute “Mary has a cat” by stating, on the basis of an observation, that “Mary has a rabbit”.

The same procedure works for other forms of opposition:
— Contradictory statements. In the sexual regime of  the19^th century one refutes « Marie is a woman » by observing that Marie is a man. The opposition is refuted by establishing that the contradictory proposition is true.
— Terms in the relationship of possession/deprivation. I am accused of having torn off someone’s ear in anger. I ask him to come to court to show that he does indeed have both ears.

The verified presence of an opposite makes it possible to eliminate all the other concepts of the family of opposites to which it belongs. This argument has immense scope, it constitutes the standard refutation system for false statements concerning  judgments of elementary facts.

The assertion of a generic concrete fact, “all Syldaves have red hair” is refuted by the counter example, by finding a Syldave with black hair. This generic refutation is in principle much easier than refutating a claim about a singular case: any black-haired Syldave will do in the first case, while the singular claim requires concrete knowledge of the being mentioned.

Resistance to refutation by facts — Resistance to factual refutation by facts is first achieved first by maintaining the original factual assertion, « to me he has red hair. »  It is then accepted that there is a blurred area between brown and red.

3. Effect of facts on theories and beliefs

Facts can be deconstructed and reconstructed to fit theories, and conversely, theories can be revised to fit facts.

3.1 Saving the theory

But, at least in the field of the human sciences, the opposite observation that the opposite is actually true, is less conclusive than it appears. The theory asserts, directly or indirectly, that P. However, common sense and linguistic intuition tend to notice rather Q, something that contradicts P. Several options are possible to get out of the dilemma.

— Reject the theory, but this is a costly and painful solution.

— Downplay the inconvenient fact, by contrasting it with the mass of facts that confirm the theory, or that the theory satisfactorily explains or coordinates.

— Put the inconvenient fact on hold until it can be integrated into the theory.

— Allow exceptions, and move from universality to generality. In classical logic, you cannot argue that “all swans are white” and concede that this particular swan is black. The quantifier all indicates that the proposition is universal, and the existence of a black swan conclusively disproves the universality of the proposition; you must then abandon universality for generality, which allows for exceptions, see reasoning by default.

— Reform the intuition, and decide that the theory is brilliant, precisely because it makes us see things “differently”, in a richer and deeper way, and that in fact P is a kind of deep structure of the elementary intuition expressed by Q. In other words, one can resist refutation by choosing to reform the internal hypotheses (the theory) or the external hypotheses (what counts as a fact).

3.2 Belief resists the facts that are held against it

Predictive discourse is in principle subject to the control of facts: someone predicts that a certain event will, or must, take place, but when the time comes, everyone can see that nothing happens. The end of the world is predicted for next Wednesday, but Wednesday comes, the world goes on, and the prophet postpones the fulfillment of his prophecy.

“Facts do not penetrate the world in which our beliefs live”

The “worship” that Mr. Vinteuil devotes to his daughter despite her scandalous behavior inspires the following lesson in Proust.

Facts do not penetrate the world in which our beliefs live; they did not give rise to these beliefs, nor do they destroy them; they can inflict the most constant denials on them without weakening them, and an avalanche of misfortunes or illnesses following one another without interruption in a family will not make it doubt the goodness of its God or the talent of its doctor. But when Mr. Vinteuil thought of his daughter or himself from the point of view of the world, from the point of view of their reputation, when he tried to place himself in the rank they occupied in the general esteem, then he made this judgment of a social nature exactly as the inhabitant of Combray who was most hostile to him would have done, he saw himself with his daughter in the lowest depths. (Marcel Proust, Swann’s Way, 1913[1])

The first sentence of this passage is the most often quoted. It is followed by a but of this passage suggests that things go further than simple suppression, or repression. “The facts” do not change the love that Vinteuil has for his daughter, but he « sees himself with his daughter in the lowest depths. » The facts remain there, under the ‘I know, but still’ rule.

Persuasion can resist the basic facts that are opposed to it.

If the claim put forward corresponds to an experimental result, it is refuted by repeating the experiment, only to find that what actually happens has nothing to do with what was said, or that the experiment, as described, does not work.

But it is not enough that it work irrefutably in order to be accepted, as the case of Ignaz Semmelweis (1818-1865), “the inventor of hand washing” proves.

In the 19th century, women often died of childbed fever. The Central Hospital of Vienna had two maternity wards, and it was found that women died much more in one than in the other, 11.4% for Ward #1 compared to 2.7% for Ward #2, for the year 1846. This difference was explained by the hypothesis of a psychological shock suffered by the women in ward #1; the priests who attended to the women at the time of their death had to cross the entire ward, where the mortality rate was particularly high, whereas in the other ward, they could go directly to the bedside of the dying women, without being noticed. Semmelweis, a pysician at this hospital, tested this hypothesis by asking the priests to stop going through that ward to get to the bedside of the dying; the mortality differential remained the same.

He observed that Ward #1 was used for the training of medical students, who performed dissections in the morning before caring for women in the maternity ward. Ward #2 was used for the training of midwives, who did not participate in the dissection sessions. Semmelweis noticed that his fingers had a strange smell after these dissections; he therefore washed his hands in a solution that we would call disinfectant, and asked each of the students to do the same. Results: in April 1847, in Ward #1, 20% of women died of childbed fever. Beginning in May, after the introduction of hand washing, the mortality rate in the same ward dropped to about 1%

This fact has a persuasive force that one might believe to be irresistible. But fact is one thing and beliefs another. How can we accept that the hands of doctors who bring life can also bring death? Twenty years later, some of Semmelweis’s colleagues still attributed the mortality of women after childbirth to a psychological shock due to their special sensitivity.

Powerless proof: The wolf and the lamb

La Fontaine’s fable The Wolf and the Lamb (Fables, i, X) illustrates is about the persuasive force of facts, and argues that proof is powerless when vital needs are at stake.

The reason of the strongest is always the best:
We will show you right now.

Situation:

A lamb was quenching its thirst
in the course of a pure stream.
A wolf came along, hungry and looking for adventure,
attracted by the hunger in those places.

The interaction begins with a violent reproach, as humans usually do to their future victims:

“Who makes you so bold as to disturb my drink?”
Said the animal full of rage:
“You will be punished for your temerity.”

The offense is presupposed (you are disturbing my drink). The request for an explanation of the motives ([what is it] that makes you so bold?) seems to leave the lamb a possibility of justification, but it is immediately followed by the condemnation (you will be punished for your temerity). This speech is mysterious: why does the wolf speak? He could simply make use of the food he was seeking and which he finally found; he could eat the lamb just as the lamb drinks the water. The lamb responds with an observation of obvious fact :

— Sire, replies the lamb, may Your Majesty
not be angry;
But rather that she consider
That I was quenching my thirst
In the stream,
More than twenty paces below Her,
And that consequently, in no way,
I cannot disturb her drink.

The conclusion is rigorous, since the laws of physics say that the stream never returns to its source. But “conclusive” does not mean “impossible to contradict”. The wolf repeats its first accusation and adds a second one:

“You do disturb it,“ said the cruel beast,
“And I know that you have been speaking ill of me for the past year.”

The lamb rejected this second accusation, then a third, still conclusively:

“How could I have done so if I had not been born?”
“I am still sucking my mother’s breast,” said the lamb.
“If it wasn’t you, then it was your brother.”
“I don’t have one.”

But the final attack is irrefutable, leaving the defense no room to respond:

“So it was someone close to you:
For you hardly spare me,
You, your shepherds, and your dogs.
I’ve been told: I must take my revenge.”

And we conclude that good reasons do not determine the course of history:

Thereupon, deep in the forests
The wolf prevails, and then eats him,
Without further ado.

Truth and Power

The previous examples may seem depressing. Facts also says that truth has enemies and needs interpreters.

[1] Marcel Proust, Du côté de chez Swann, T. 1. Paris, France Loisirs, p. 226.