PK Rangachari, Professor Emeritus of Medicine, talks about his course HTHSCI 4MS3 - Toxic Tales: The Social Life of Molecules, which explores 'molecular sociology' -- the idea that molecules are not just scientific entities, but social ones as well.  The things we label as foods, cosmetics, drugs, and poisons are all just molecules as far as our cells are concerned, and they respond according to the receptors they possess, the concentration of the substance, and the pathways that are activated; but they take on different meanings only in a social context.  This course challenges students to recognize that narratives are an important part of science, and how science and society are irretrievably intertwined.