EFFECT-TO-CAUSE Argument

The word consequence can mean:

— Effect, referring to a causal, cause/effect relationship S. Causality.
— Consequent, referring to a logical, antecedent/consequent relationship, S. Connectives, §Implication

1. Effect-to-cause argument

Other expressions can also be used, such as argument by the effect, or from the effect to the cause, see also A priori, a posteriori.
The effect to cause argument works backwards from the effect to its cause. Given data is considered to be the effect of a hypothetical cause that can be reconstructed on the basis of this data combined with a known causal relationship between this type of facts and its cause.

You have a temperature, therefore you have an infection

— Argument: A confirmed fact t, the patient’s temperature. This fact t belongs to the category of facts or events T, “having a temperature”, as defined by medicine. This is a process of categorisation.
— Causal Law: There is a causal law linking I facts “having an infection” to T facts, “having a temperature”
— Conclusion: t has a type T cause, an infection, and the patient should be treated accordingly.

This corresponds to the diagnostic process; one might speak of diagnostic reasoning.

The effect (the temperature) is the natural sign of the cause. Such natural, palpable, effects provide endless basis for argument by natural signs:

Look! The ashes are still hot, there was a fire recently (… they cannot be very far away)

In the field of ​​socio-political decision-making, the argument by consequences corresponds to the pragmatic argument, which transfers the positive or negative evaluation of the effects of a proposed measure to the measure itself.

The pathetic argument scheme is a special kind of pragmatic argument arguing from the fact that « rain would ruin our party » to the claim « it won’t rain”, as if my wishes could influence the natural course of things.

2. Arguments by the identity of the consequences

The same type of argument applies to deductions made from the implied meaning of words, as an appeal to the sense of semantic coherence or logical consistency:

Topos: “Another topic consists in concluding the identity of precedents from the identity of results”
Instance: “There is as much impiety in asserting that the gods are born as in saying that they die; for either way the result is that at some time or other they did not exist” (Aristotle, Rhet. II, 23, 1399b5; F. p. 313-315).

 If the reason given for banning the consumption of marijuana is that it causes a loss of control, then all substances that cause a loss of control must also be banned, including for example alcohol. If something is condemned because it forcibly involves mechanically something negative, then it automatically creates a category of causes “having that kind of negative consequences”, which must also be condemned.

3. Refutation by contradictory consequences

The refutation by contradictory consequences is a kind of ad hominem, used in dialectic:

Peter says “S is P”.
S has the consequence Q: the fact is known and accepted by the opponent.
P and Q are incompatible.
So Peter says incompatible things about S.

Example:

Pierre says that power is good.
But, everyone agrees that power corrupts (consequence)
Corruption is an evil.
Good is incompatible with evil; to be good, power should exclude corruption.
Peter says contradictory things.