can do, ignore the complexities of social and institutional constraints, often waste sums that would have been better spent more carefully and wreak havoc with the existing fabric of society in places they know very little about.” Moreover, they are not immune to fashion, delusion, corruption, and arrogance. Nor are they often held accountable to

Before effective medicines were invented, HIV killed more than 95 percent of people it infected, making it the most lethal virus the world had ever seen.3 But HIV took years to wreak havoc, so infected people could pass it on without knowing they were sick.