This paper introduces the special issue by first reviewing the cultural climate and the scientific ancestors that suggested title and contents. These are aimed at the core of the dynamic origins of natural form and function (or, as in often abused words, "how nature works"), seen through the perspective of hydrologic research. An overview of the invited contributions follows, which includes a subjective explanation for the conceptual thread that joins them. Key to the contents of the invited papers is the future role of hydrology within the geosciences. Such a role is argued to be of growing importance owing, on one side, to the objective social and economic relevance of hydrologic matters (a fair distribution of water resources, flood and droughts among them) and, on the other, to the quality and the spatial/temporal extent of hydrologic data, which have been indeed instrumental in the radical change we recently experienced in the way we perceive and measure natural phenomena.