Archaeologia Britannica, Giving Some Account Additional to What Has Been Hitherto Publish'd,... Book

Probably the most mind-blowing book I read when I was an undergrad and one of the few that I find myself going back to again and again. Smith does for morality what Darwin did to biodiversity - took a phenomenon widely assumed to have been bluntly imposed from above and showed it to be rather something that naturally emerges from the interaction of individuals endowed with certain properties (in this case, instincts both for self-preservation and empathy/sympathy). I finished with an exciting way to conceptualize human relations, and greater skepticism for claims that morality is "just a cultural construct" that can be discounted or arbitrarily molded.