- No Platonic Form can have a property with which it is not identical (3 cannot be 7, 7 cannot be green, greenness cannot be smaller than rudeness, etc).
- A Platonic Form is a Universal, and a Universal is a Platonic Form.
- A Universal is that which can be said of many (this includes adjectives, prepositions, substantives, etc.).
- Existence can be said of many.
- Therefore, existence is a universal (a Platonic Form).
- Platonism (Platonic Realism) claims that all Platonic Forms exist.
- If all Platonic Forms exist, then at least one Platonic Form has a property with which it is not identical (namely, existence).
- Therefore, Platonism (Platonic Realism) is wrong.