This book has attempted to explicate three different types of reduction (and reductionism) that have been relevant to genetics and to assess their relative strengths and weaknesses. The conclusions reached for each of these types have been stated in each of the previous three chapters. No further conclusion is strictly necessary, though some further consequences of those conclusions will be listed in the third (and final) section of this chapter. Meanwhile, the first two sections of this chapter will explore some topics that deserve more attention than what has been given to them so far. In particular, recalling that the stage for the discussion of reductionism in genetics was set at the beginning of this book by noting how claims that various traits are “genetic” have become pervasive in recent years, an attempt will be made here to define that term.

To develop the background necessary for that proposed definition, § 7.1 will draw some distinctions about biology, genetics, and inheritance. These are relatively trivial but, as an example given there will show, they have far too often been ignored during the recent excitement over the prospects for genetic reductionism. This will set the stage for § 7.2 where a (rather restrictive) proposal for the use of the term “genetic” will be made. Such a proposal is important mainly because of a social context in which claims of the genetic basis for traits are being made with increasing frequency (see Chapter 1) and, especially in the popular press, with little concern for any of the subtleties or nuances that were emphasized in Chapter 5, § 5.5 and § 5.7.