Rostislav Sergeevich Il’in: A soil scientist and geologist ahead of his time

The most important aspects of the research of Il’in that turned out to be ahead of his time are analyzed. These aspects are as follows: the relationships and simultaneous development of surface rocks, relief elements, and soils; the integrity of the development and hierarchical spatial-temporal variability of landscapes; the continuous displacement of natural zones (evolutionary and revolutionary, when moving to the equator and poles, respectively); the succession of climatic phases of the geological cycle—from the interglacial xerothermic phase to the glacial cold and humid one separated by transitional phases with a temperate climate; and the complex subaerial-stream theory of the origin of loess.