Negative ontology. Zoontology -- Existence is not a proper property -- What is wrong with Kant and Frege? -- Limits of set-theoretical ontology and contemporary nihilism -- Domains of objects and fields of sense -- Fields and the meaning of existence -- The no-world-view -- Positive ontology. Indefinitely many fields of sense -- How flat can ontology be? -- Actuality and Possibility -- Modalities II : necessity, contingency and logical time -- Forms of knowledge : epistemological pluralism -- Senses as ways things are in themselves.