A law that states that all things must be made to proportions, for example letter paper in proportion to envelopes or size doors to size door entrances. Furniture in relation to door entrances in relation to shipping space and so and so on. In materials engineering the machining material must be in proportion to the cutting tools otherwise the tool will fail to cut the material.
When proportions are thought of liken to common sense, all will flow well. When their is a proportion issue friction will result.
This is not a law of politics, it is a consideration of manufacturing.