"A nutritionist may see malnutrition but not the seasonal indebtedness, the high cost of medical treatment, the distress sales of land, and the local power structure which generate it. A doctor may see infant mortality but not the declining real wages which drive mothers to desperation, still less the causes of those declining real wages. Visibility and specialization combine to show surface symptoms rather than deeper combinations of causes. The poor are little seen, and even less is the nature of their poverty understood."