Aristotle seeks to determine what it is to be a substance. He ends up concluding that it is to be its essence or form. The definition of an essence is stated all in universal terms. Yet Aristotle insists that no universal is a substance. These claims can be made consistent if a definition is taken as a statement of the essence, in the sense of predicating something of it. For Aristotle predicates are typically more general than their subjects. In this way Aristotle can have a science about individuals consisting of universal statements.Individual substances alone exist in their own right. Everything else, secondary substances and accidents, universal or individual, exist only due to their being related to those individuals. Aristotle's theory of paronymy clarifies this dependence. Universals have a natural basis: the world has regularities of type; an individual animal reproduces different individuals of the same type. The essence or form of an individual substance has both universal and singular aspects but is not itself universal. As in the medieval doctrine of the threefold distinction of quiddity , Aristotle's essence of the individual is neither one nor many. Aristotle's views on abstraction play a large role here: the constituents of an individual substance , its form and matter, are abstractions and have a dependent, relational existence; likewise the universals of science are aspects of individual substances .