  The eighth of the nine Vaiśeṣika types of substance is ‘self’ (ātman), defined as the substratum of mental states such as believing, knowing, etc. (The ninth is ‘mind’ (manas), a distinct element in the ontology of the mental.) Selves are divided into two types—human (jīva) and divine (paramātman; īśvara). The Manual of Reason supplies arguments (all traceable back to earlier authors) for the existence of both types of self.