 In Psychology (PES 212 fn, [II 54 fn; SVS 1, 234 fn 246]) Brentano says in a long footnote that Aristotle hinted at the right conception of existential judgement in Metaphysics and in De Interpretatione. In Metaphysics Book IX (θ) 10 Aristotle is faced with a problem. He has told his readers that one judges truly if one separates in thought what is separated in reality and combines in thought what is combined in reality. For example, if Plato and foolishness are separated—the former does not have the latter—one judges truly if one separates Plato and foolishness in thought, that is, judges that Plato is not foolish. But now Aristotle goes on to tell us that there are incomposites that are not combined with anything. How can one make true or false judgements pertaining to such  things?[10]