Causes are defined informally to be events which are both contextually necessary and contextually sufficient for their effects. A formal, logico-pragmatic, definition is then given and discussed.

Describing and explaining are two very different engagements, and yet development experts routinely write as though to describe were to explain. If this were not the case, it would be hard to understand why they have found it necessary to repeatedly describe the lives of the world’s poorest over the past 30 years. Consider the following sentence constructed from numerous writings—for example, b...