Criteria of Abstractness. The Ontologies of Husserl, Frege and Strawson against the Background of Classical Metaphysics

In analytic philosophy someone tends to be called a Platonist if he assumes that there are abstract objects. It has been asked what condi-tions must be fulfilled for someone to be correctly called a Platonist, or for a theory to be Platonistic in this sense. In the ontological discussion devoted to this question, a discussion which has sometimes resembled shadow-boxing, the question 'what is an abstract object? ' has been al-most completely neglected. It is this question which will occupy us in the present essay. We begin with a rather unassuming answer. That abstract entities at least include those entities designated by the italicised portions of the following sentences: (a) Properties (Attributes) Bravery is a virtue. Being courageous is something different from being foolhardy. (b) Rela tions How does friendship cliffer from love? (c) Propositions Given that the Earth is smaller than the Sun, it follows that the Sun is bigger than the Earth. Did Pythagoras prove Pythagoras ' Theorem? Xanthippe doubted the courage of Socrates. What you just asserted is not true. (d) Genera and Species The whale is a species of the genus mammal