Cause – Effect relationship: The Causal Link at issue

1. Causal argumentation

Cause-to-effect or effect to cause arguments presupposes the existence of a causal link, while causal argumentation establishes the existence of a causal link.

Causal argumentation occurs when a causal link is at issue.

For example, we notice that, on the one hand, (1) that the use of pesticides is intensifying, and (2) that bees are disappearing. Is there a causal relationship between these two facts, are the following statements true?

The use of pesticides causes the disappearance of bees.
Pesticides are used and bees disappear (causal reading).

There may be disagreement about this kind of conclusion, even if there is agreement on the facts under consideration:

We use pesticides and the bees disappear, that’s true. But…

The causal investigation starts with a salient fact, as “bees disappear”, “the climate seems to be changing”, and the cause of this is problematic. Generally, several facts can be evoked as possible causes, and possible explanations of the phenomenon. This creates a stasis of causality, expressed via the confrontation of these two hypotheses, for example in the case of climate change, taken as a fact:

S1:    — the increase in solar activity causes the change of climate.
S2:    — the increasing emission of greenhouse gases causes climate change.

These explanatory causes integrate themselves within broader theories on the climatic equilibrium of the terrestrial globe. Broad conceptions of the physical and social world are in confrontation through such local causal affirmations.

Affirmation of causal relationships are therefore based on elaboration of crucial experiments and the retrieval of key observations. Causes are determined according to the methodology relevant to the given domain.

Ordinary causal experimentation also involves observation and experience. So for example, if I suffer a mild allergy reaction, I must consider what the possible allergens might be which have caused it. I might observe that yesterday I went to the swimming pool and ate strawberries. There are two possible allergenic, strawberries or chemical products used in the pool. I might conduct the following checks, eating strawberries without going swimming, and going swimming without eating strawberries. If I am unlucky, I’ll have to investigate further and perhaps see a specialist, who will proceed in much the same way. If I am lucky, however, I’ll suffer a (controlled) mild allergic reaction in one case and not in the other, and will be able to identify the allergen. As the allergic reaction is undesirable, I pragmatically reason, in view of the negative consequence, I change my behavior, and so eliminate the cause.

2. Refutation of causal assertions

The correct establishment of causal relationships is a fundamental requirement, both in science and in ordinary life. The priority given to the correct determination of causal relations is the basis of Aristotelian thought. The “false cause” fallacy is committed when a causal relation is asserted between two phenomena that in fact have no causal relation between them. This fallacy is sometimes designated by its Latin name non-causa pro causa, “‘non-cause’ taken for a cause”, S. Fallacious (2).

Smoking causes cancer”: strictly speaking, the positive existence of such a relationship is difficult to establish. It can only be considered as a remainder, persisting when all other possibilities have been discarded. Causal imputation might be revised. If we are to confirm that a link of the causal type does exist between two facts, it is necessary to answer a set of standard objections which oppose the existence of a causal relation.

2.1 The alleged effect does not exist

The causal assertion “the use of pesticides is the cause of the disappearance of the bees” is refuted by showing that although the bees have disappeared from a certain area, there are still as many bees as before if a larger, more general area is considered. The bees have not disappeared, they have simply migrated.

The facts must be confirmed, before looking for and discussing their causes. This methodological rule is well illustrated by the famous case of the golden tooth, described by Fontenelle.

Let us be well assured of the matter of fact, before we trouble our selves with inquiring into the cause. It is true, that this method is too slow for the greatest part of mankind, who run naturally to the cause, and pass over the truth of the matter of fact; but for my part, I will not be so ridiculous as to find out a cause for what is not.
This kind of misfortune happened so pleasantly, at the end of the last age, to some learned Germans, that I cannot forbear speaking of it. “In the year 1593, there was a report that the teeth of a child of Silesia of seven years old dropped out, and that one of gold came in the place of one of his great teeth. Horstius, a profesor of physic in the university of Helmstad, wrote in the year 1595, the history of this tooth, and pretended that it was partly natural and partly miraculous, and that it was sent from God to this child, to comfort the Christians who were then afflicted by the Turks.” Now fancy to your self what a consolation this was, and what this tooth could signify, either to the Christians or the Turks. In the same year, (that this tooth of gold might not want for historians) one Rullandus wrote the history of it: two years after, Ingolsteterus, another learned man, wrote against the opinion of Rullandus concerning this golden tooth; and Rullandus presently makes a fine learned reply. Libavius, another great man, collected all that had been said of this tooth, to which he added his own opinion. After all, there wanted nothing to so many famous works, but the truth of its being a tooth of gold. When a Goldsmith had examined it, he found that it was only a leaf of gold laid on the tooth with a great deal of art. Thus they first compiled books, and then they consulted the goldsmith.
Nothing is more natural than to do the same thing in all other cases. And I am not so much convinced of our ignorance, by things that are, and of which the reasons are unknown, as by those which are not, and for which we yet find out reasons. That is to say, as we want those principles that lead us to the truth, so we have others means that not only do we not have the principles that lead to truth, but we have others which are exceeding well with that which is false.
Bernard Le Bouyer of Fontenelle, The History of the Oracles [1686][1],

2.2 The effect exists independently of the alleged cause

The determining cause has a consistent impact. If C is the cause of E, we cannot have C without E. If a metal is heated, it necessarily expands. It follows that a causal statement can be rejected by showing that the effect persists when the cause is absent. To refer again to the example above, if it can be shown that bees also disappear from areas where pesticides are not used, pesticides cannot be considered to blame for the fall in bees’ number.

2.3 There is no causality but concomitance

In that case, A both regularly accompanies and precedes B without being the cause of B. The cock sings regularly before the break of day, but it is not the cause of the sunrise. Taking an antibiotic might be accompanied by a feeling of exhaustion, but the cause of this exhaustion is not the antibiotic but the infection that it fights. The general principle to check whether a causal relation exists is to suppress the agent which is the suspected cause; if the so-called effect is still there, there is no causal link between the two facts. If the cock is eliminated, for example, the sun still rises; if we do not take antibiotics, we will still be exhausted and perhaps even more.

The use of pesticides is concomitant with the disappearance of bees; but in areas where pesticides cease to be used, bees’ numbers continue to fall at the same rate. The cause is to be sought elsewhere: perhaps climate change is to blame?

Such erroneous causal imputation are well identified in the ancient theory of fallacies, which denotes them by two Latin expressions:

— Fallacy of the antibiotic: cum hoc, ergo propter hoc:

with A, therefore because of A”: A accompanies B, so A is cause of B.

— Fallacy of the cock: post hoc, ergo propter hoc:

after A, therefore because of A”: B appears after A, so A is cause of B.

2.4 Another cause may have the same effect

One can be tired because one has been physically exhausted, because one has an infection, or because one is depressed.

2.5 Not one, but several causes: complex causality

It may be necessary for several causes to exist in conjunction in order that they produce some effect. This is the case of economic crises, or lung cancer.

The determination of causes establishes the responsibility of the human agents who have set the causal machinery in motion. If the causality is complex, it is possible for the defendants to argue that they are responsible only for a causal factor, which would not alone have given rise to the relevant problem. Upon being arrested, a person dies. The autopsy shows that this person was suffering from a weak heart:

Lawyer:    — If the police had treated him gently, he would not have died. The police are responsible.
Police:      — If he had not been sick before, he would not have died. The police are not responsible.

In cases of heavy pollution, the authorities apologize to people suffering from respiratory diseases: “people without such respiratory issues have no problem”.

2.6 The effect feeds the cause

Feedback is a sort of causal circle: atomic fusion raises the temperature and the rise of temperature accelerates fusion. In the social field, this kind of mechanism is invoked to reject a particular measure, arguing that it will not alleviate the issue in question, but rather aggravate it:

L1:      — To fight recession, public services must be strengthened / reduced.
L2:      — But the strengthening / reduction of public services will reinforce the recession.

One can always refute a measure by asserting that it will have certain unwanted consequences which will outweigh any potential advantage, S. Pragmatic argument. In the example given above, the refutation is radical, the perverse effect being not a side effect, as yet unnoticed by the author of the proposition, but exactly the reverse of the intended effect. This is a case of pure and simple inversion of causality (see infra), which is frequent in polemical discourse.

2.7 Self-fulfilling prophecies

In the case of self-fulfilling prophecies, the announcement of an event is the cause of the event:

S1_1:     — In truth, I tell you: there will be a food shortage!
So people run into the shops and there is a food shortage.

S1_2:     — You see, I told you so!
S2:        — If you hadn’t have caused the people to panic, there wouldn’t have been a shortage.

Self-fulfilling prophecies are close to manipulation:

We are certainly going to war, so we must rearm and warn the population. … Now we are the strongest, and our people are behind us. We can wage war.

2.8 Conversion of cause and effect

The reversal of cause and effect is a form of refutation common in ordinary argument. Two facts A and B vary concomitantly. To account for this concomitance, some assert that there is a causal link from A to B, others claim a link from B to A. The protagonists defend the converse propositions, “A is the cause of B” and “B is the cause of A”. Do we cry because we are sad? Or are we sad because we cry? Does aggression provoke fear? Or does fear result in aggression?

L1:        — I am afraid of dogs, they can attack and bite!
L2:        — No, they attack because they see that you’re scared.

L1:        — OK, I’m aggressive, that’s because they persecute me!
L2:        — No, they persecute you because you’re aggressive.

In the first case, the affair originates with the dog and the supposed bully, in the second case with the self-claimed victim. It is said that single people are more likely to commit suicide than people with a partner. We might therefore ask whether single people have such problems because they are single, or whether they are single because they have such problems? This form of refutation by permutation of the cause and effect is simple and radical. It is worth noting, however, that it is not always possible to apply this process, as seen above, in the case of bees and pesticides.

This causal shift is particularly popular in ordinary causal argumentation. This play on permutation of terms illustrates the pervasiveness of language-based argumentation schemes. It is easier and more exciting to argue that politics determines morality or that morality determines politics, than to argue that there is no link, or very complex ones, between morality and politics, S. Converse.

2.9 Causality, subjectivity, responsibilities

The causal chain might be badly cut: the expression of causality as “A is the cause of B” is a potentially misleading simplification. Every cause is itself caused, except God, who is said to be his own cause and cause of all that ensues. The phenomenon designated as the cause can itself be constructed as the effect of a deeper cause, and its effects as new causes of new effects. We are therefore not dealing with a link between two terms, but with a real causal chain of potentially infinite length.

Consider the deadly events which took place in Sheffield on Sunday, April 16, 1988. They were extensively reported and commented on in the French press. On the following day, the front page of L’Équipe (a sports newspaper) read as follows:

The Horror!
Eighty-four people were killed on Saturday in Sheffield stadium, where the Liverpool-Nottingham FA Cup semi-final took place.

Typically, this kind of event causes anxiety which in turn stimulates the search for causal explanations. Readers will ask themselves “Why? How can such things be possible?” The same day, the headlines in Le Figaro newspaper (news and opinions) were:

Football: Why so many dead?
Four explanations for the drama:

    • The madness of supporters • Police negligence
    • The age of the stadium • Inadequate relief

The answers provided in the newspaper refer to a broad causality for the first question, and to a narrow causality for the others. The same day, the newspaper Libération (news and opinions) asserts a broad causality:

94 dead in Sheffield stadium
Deadly stadium
Crushed to death by the throng of supporters, victims who had come to see the Liverpool-Nottingham Forest football match made a dramatic tribute to the most popular sport in Thatcher’s Britain.

Still the same day, L’Humanité newspaper (news and opinions) combines local causes and so-called deeper causes:

After the drama of Sheffield, Liverpool in mourning
The Last Stage of Horror

90 dead and at least 170 wounded, such is the appalling toll of the Hillsborough catastrophe. The vast majority of victims are children and young people from working class backgrounds who had come to support their teams. The age of the stadiums and their segregational character, and the hold that money has on the world of football are now in the dock. The destruction of industry and the resulting disorganization of leisure activities all have their share of responsibility in the transformation of sports into high-risk activities.

Examination of the causal chain mobilizes specialists in each of the areas of responsibility mentioned. Police officers and judges investigate narrow causalities, whilst sociologists, economists, politicians and historians discuss long-term causalities and responsibilities. In short, what is the cause? The fragility of the victims’ rib cage, the poor quality of care to victims, the tardy response of the emergency services, the incompetence of the police services, the poor standard of the stadium, the financial greed of the organizers, the supporters’ behavior, unemployment, social exclusion, the capitalist system…? To assign a cause is to assign responsibility and apportion blame and perhaps even bring shame upon the relevant parties. This case shows that causality functions as a discursive object, S. Cause — Effect.

Moreover, the causal chains intermingle and combine into a “fabric of causes”. Argumentation is based on this fabric, as “causal threads” are picked up and cut at a given point. This point determines the nature of the chosen cause attached to the salient problematic event considered as an “effect”. The selection of a cause, correlatively, determines the responsible agent, person or institution, to blame or to praise. All the process depends on the interests and aims of the arguing party. The speaker fully projects his own subjectivity on the causal chain he or she has selected, and on the cause he or she has isolated. It would therefore be quite illusory to consider that ordinary arguments based on causal links are ipso facto more rigorous and less subjective than arguments based, for example, on analogy.


[1] Bernard Le Bouyer of Fontenelle, The History of the Oracles. Glasgow: R. Urie, 1753. P. 14-15.