Definition property/self-identity/sameness/Millikan: the identity of the properties of an individual is determined by natural opposition to these properties, based on that individual.
Definition Individuals/Self-identity/Sameness/Millikan: the identity of an individual is defined by the fact that it naturally has the qualities it has.
The identity of an individual is determined by the rejection of contradictory properties.
A self-identical individual has exactly one property from each property domain, whereby the property domains are mutually exclusive._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution.
R. G. Millikan
Language, Thought, and Other Biological Categories: New Foundations for Realism Cambridge 1987