The difficulty of distinguishing between an inference and a presumption, a difficulty that bedevils tort and evidence teachers, (see Appendix I) among others, may be dispelled by a study of the deontic nature of permissible inferences and presumptions. Using scholastic terminology, an inference is a function of the intellect, not the will. Therefore, deontic notions of permission and duty seem foreign to inference. However, deontic notions are legitimate, because the law, in assigning a fact finding function to judge and jury, uses deontic notions in assigning fact finding competence. Thus, the statement that an inference is not permissible means that insufficient evidence has been introduced to permit the jury to find the fact in question. It does not matter whether the jury, by applying its collective intelligence, would draw the inference. Their incompetence to draw the inference is not a function of rationality, but of a rule of law that deprives them of competence.
Finan, John P.
"Presumptions and Modal Logic: A Hohfeldian Approach,"
Akron Law Review: Vol. 13
, Article 2.
Available at: https://ideaexchange.uakron.edu/akronlawreview/vol13/iss1/2