 A similar point is made in connection with the use of modal terms. For Peter of Spain, logical necessity is based upon ontological necessity, or, the necessity of propositions has its foundation in the necessity of the things spoken about. Necessity is associated with different types of things, such as the relationships between certain concepts (such as genera and species), and the specific things the notions of which we come across in the different kinds of (scientific) knowledge (such as mathematical entities and their properties). His outlook on necessity is clearly revealed in his analysis of the inference homo necessario est animal; ergo Sortes necessario est animal (‘A man is necessarily an animal; therefore Socrates is necessarily an animal’). In his view the inference is not valid, because a transition is made from necessary being to a being at a certain time. For Peter then, the notion of necessity ultimately refers to a necessary state of affairs in reality, something that is always the  case.[6]