 For Aristotle, the general premises of scientific explanations are generalizations that describe commensurately universal properties of things of a subject kind, \(K\). Merely universal properties are ones that everything of kind \(K\) has but could be without and remain a thing of that kind, just as every Honda might have Michelin tires. Aristotle referred to such properties as “accidental”. Commensurately universal properties are ones that belong to everything of the kind as necessary attributes that they cannot be without. A triangle, for example, has three lines and angles. Aristotle referred to them as “essential”. Because generalizations about the essential properties of things of a kind are “proper definitions”, they provide the basis for explanations that qualify as analytic. Hempel encompassed analytic generalizations within the scope of “fundamental laws” as defined in Hempel and Oppenheim (1948), but he focused on those that were synthetic.