Insightful discussions on pleasure, addiction, and societal implications can be found here. The level of scientific language may put off the typical layperson. Reads like an abstract of a scientific paper in some sections, with too much repetition of phrases of substances involved, which is an attempt to be precise but often just clutters the landscape and hinders clean absorption of the material. Historical sections are much more reader-friendly, interesting, and provocative, showing how fluid social morality is, esp. with respect to pleasure-inducing chemicals and activities.