Here Kripke extends the ideas developed in his account of identities between proper names to terms for properties and kinds.

• First he returns to the discussion of essential properties of an individual (pp. 110-114).

• He then turns to what he calls "theoretical identities" (i.e., scientific statements of identity between certain general terms) and to ascriptions of essential properties to whole kinds of things. In the course of this discussion, he addresses the meaning of natural kind terms (i.e., terms for natural groupings of objects, such as biological species) and gives an account that is analogous, but not identical, to his account of proper names. To shorten the assignment, you can skip the first 20 pages of the discussion and pick it up again on pp. 134-140, where he summarizes the five main points of his account of natural kind terms, and then goes on to state his views on theoretical identities (pp. 140-144).