Chatton thinks that there are ten categories and that they are those ten, namely substance, quantity, quality, relation, time, place, action, passion, position, and state or having, because there are ten basic classes of real things for which we construct specific definitions, the terms of which come out of the categories. The categories are devised to define and thus neatly map onto ontological classes. Chatton disapproves of Ockham’s contention that there are ten categories for only two sorts of things, substances and some of their qualities. To establish his ontological claim, Chatton argues for each class on a case-by-case basis, employing the Chatton Principle (see above 3.2). He had already done this in the case of relations in the earlier Reportatio, arguing that we are ontologically committed to certain classes of relational entities in order to make the propositions “a heat causes heat” or “the soul causes an intellection” and “Plato generates Socrates” true. Now, in the Lectura, he argues that we must grant the existence of substances, qualities, and quantities as really distinct from one another as well as from relations, which include not only relations proper but also the six kinds of relations picked out by the last six categories, namely time, place, action, passion, position, and state. Here is a reconstruction of his argument for quantities found in Lectura 1, d. 8, q. 1, paragraph 109: