So can we conclude that law makes a difference to global health challenges? Our special symposium provides no definitive answer but instead adds complexity to the question. The contributions oscillate between shades of optimism and pessimism. Optimistic stories of the success of law — or at least its potential — high- light the interplay between international agreements, international monitoring and governance, domestic health human rights and litigation, and the role of NGOs. However, even the most optimistic commentators admit that success is hard won and frequently decades in the making, such as for example, in the case of tobacco control. This seems likely to be the case (and success certainly cannot be assumed) for new global challenges such as obesity. Several sub- themes emerged as contributors explored optimistic scenarios. One theme, raised by Aeyal Gross and bearing further exploration, concerns whether the courts are more likely to be protective of health human rights that exist as part of government policy as opposed to ensuring the realization of these rights when not in place. The success of tobacco control litigation would seem to fall in line with this theme as demonstrative of courts protecting existing government policy but not catalyzing progressive change. Yet another sub-theme, raised by Mariana Prado, is whether litigation, which seems to undermine equality, might have a long-term positive knock-on effect in other areas, including the health care system and the operation of the courts. Social science research is needed to assess what the long-term impact of these changes are, even if these changes may not outweigh the immediate costs to access to care.