  In both these sorts of demonstration, Grosseteste holds, the major premise and conclusion are per se in the second way, that is, the subject is somehow presupposed in their predicates. The minor premise, since it predicates a formal definition of its subject, is per se in the first way (the subject contains the predicate). So in the case of a natural demonstration, the subject is the causal outcome of the predicate (the noise, or thunder, results from the extinction of fire in a cloud), and is presupposed in it inasmuch as the point of the material events is to produce that outcome. It is as if one were to say that the construction of an adding machine presupposes the notion that it adds, because it is in order to do this that it has a structure which causes addition. Final and efficient causation does not figure in mathematical demonstrations, but in any proper demonstration, Grosseteste thinks, the conclusion will not merely assign a predicate that belongs universally to its subject, but one that is commensurately universal with it. That is, one won't have identified the real underlying cause why a figure has a property if it belongs to some larger class of figures that have the property, unless one demonstrates that this larger class has it, and then appends, as it were, a note to the effect that the figure falls within the larger class. That means that a demonstration of the highest sort will always show a property to belong to something which not only has it necessarily, but which is also necessary to produce that property. So the conclusion and the major premise will have to be per se in the second way, for the subject will be the necessarily underlying cause of the property. Nothing else can produce it.