Arguing on Uncertainty
|Fakulta / Pracoviště MU
|Hume’s gap divided two main types of propositions: is-propositions and ought-propositions. According to this we cannot argue for an ought-proposition by some is-propositions. The same is true vice versa by so called moralistic fallacy (or reverse naturalistic fallacy). Thus we cannot argue even for an is-proposition with some ought-propositions. The uncertainty can be defined as a state in which we are unable to say that X is the case (or should be the case) pointing out only factual propositions (or norms) and in strictly rational debate we should abstain from any conclusion made that way. But there are practical reasons in real life (e.g. cases of negligence) when this abstain is not acceptable. In these cases, we do not want to depart from ratio, thus we have to find means how to bypass the gap. In the cases where the problem of crossing from ought-propositions to is-propositions is considered, the possibility lies in adding the procedural rule which makes clear which party needs to reject the state of what should be the case by presenting contradicting facts. This can be done by placing a burden of proof. Thus in some examples the party without this burden can argue for an is-proposition by ought-propositions. E.g., in a court of law this is done by presumption of innocence. In a simplified way, the defender can use the argument that he has done Y because he should have done it. On the other hand, the prosecutor has to point out contradicting evidence. Much more complicated is the situation when there is a presumption of guilt.