Abstract

The paper deals with Aquinas’ theory of intentional forms, so-called species, insofar as it gives an account of the validity of human cognitive acts. Its focus is on the objectivity of knowledge and the basis of radical (Cartesian) scepticism, therefore the comparisons to the modern theory of ideas are employed. However, the author’s aim is not a defence against scepticism; her aim is rather to provide certain insights into its origins.