Dave Rawlings completed this course, spending 9 hours a week on it and found the course difficulty to be medium.
An interesting course that comes from mainly a social psychology viewpoint, with a bit of philosophy thrown in. The quizzes cover the ground well (there is one for each week). As it is 6 years since the course first ran, the discussion boards are understandably fairly silent - although great credit for there being an active mentor on them. The main format is lectures, which are reasonably engaging, supplemented by readings/TED talks - 2 or 3 a week. I got a lot out of the course and it made me think about some moral issues that I wouldn't have previously thought about in the same depth.