The definition specifies the necessary and sufficient conditions for an object to be a member of the designated category. This classic view can be rejected on a number of grounds, including failure to find necessary features for most concepts, graded structure of all concepts, and the ability to form and use ad hoc concepts. Lakoff s analysis of the concept of mother shows the variety of ways in which a single concept can be used. The symbol for mother is inadequate to signal the precise meaning of the term.
Concepts are depauperate, a biological term meaning poorly or imperfectly developed.
There is no single or core definition of mother, rather we employ theories of what the concept means. My real mother died when I was an embryo, and I was frozen and later implanted in the womb of a woman who gave birth to me.