Brentano uses terms in place of predicates (e.g. "a thinker" in place of "thinks") and characterizes the "is" of predication in terms of the part-whole relation. Taking as his ontological data certain intentional phenomena that are apprehended with certainty, he conceives the substance-accident relation as a defmeable type of part-whole relation which we can apprehend in "inner perception". He is then able to distinguish the following types of individual or ens reale: substances; primary individuals which are not substances; accidents; aggregates; (...) and boundaries. (shrink)