Dr Sanjiv Chopra is Professor of Medicine at Harvard Medical School. He is also the James Tullis Firm Chief in the Department of Medicine and a Senior Consultant in Hepatology at the Beth Israel Deaconess Medical Center in Boston. Dr Chopra has authored more than 150 articles and seven books including bestsellers THE BIG FIVE and, with his brother Deepak Chopra, BROTHERHOOD.

David Fisher is a former writer for The Spruce (About.com) and has been making soap for nearly 20 years. He has always loved working with his hands and creating things from scratch. Soap fulfills his combined interests in arts and crafts, chemistry, cooking, aromatherapy, and frugal living.

The owner of Bath Rabbit Soap Company and a member of the Handcrafted Soap and Cosmetics Guild, Fisher teaches students of all ages how to make candles, soap, and bath and body products. He attends numerous local and regional soap and candle making conferences and classes and has logged countless hours of "in the kitchen" training in soap and candle making.

Fisher is also the author of several articles and books on the topic, including The Complete Photo Guide to Soap Making. He studied theater at California State University in Sacramento, nonprofit management at the University of Dallas, and spent three years at Tulane University.